I can explain why this is in Connecticut, as I am well versed in the early history of the state. Perhaps this can help give insight into why this is in other states, as well, but I make no promises.
Connecticut actually originally had two capitals. New Haven, a coastal city in the South West and Connecticut's historically most populous city (since overtaken by Bridgeport), and Hartford, a more centrally located city and one of the founding points of Connecticut. Both were economically viable, as New Haven had access to the ocean and New York City, while Hartford sits on a major river and is closer to the cities of Boston and Providence. So for many years the state had two state houses- one at the historical and geographical center of Connecticut, Hartford, the other in the economic and educational center of Connecticut, New Haven. By the mid 19th century, however, this became clearly unsustainable, and it was put to a vote as to where the new capital would be. By offering a plot of land and poising itself as the historical capital of Connecticut, as well as arguing that a more centralized capital would better serve the state as a whole, Hartford won out.
In short, Connecticut's state capital is only the fourth largest city in the state, trailing behind Bridgeport, New Haven, and Stamford. It is the capital, however, do to a central location within the state and historical value.
Sources
Census Data from 1850, demonstrating the size of Connecticut's cities
Official explanation for the split, from the CT state historical society
History of the city of Hartford, from the Hartford Founders Society
In the case of the United States, the western states have their capitals in central positions (like Sacramento, California , Carson City, Nevada, Pierre, South Dakota) and so on for geographic reasons and to show a sense of balance between the state. Eventually, the capitals did grow with or became bigger cities in the United States, such as Phoenix, Arizona (part of the top 10 US cities, and biggest capital city today), Boston, MA (Also if you consider the bigger Metro Area between Washington DC-Philadelphia-New York City-Boston). In the past, the US had their state capitals in bigger cities in the east too, and only focusing on one region, like New York City (after the land was ceded to the English by the Dutch), and was the state capital of New York and the US (1785-1790), or New Orleans for Louisiana.
Although this doesn't pertain to the United States, other countries had their national capitals as primate cities and moved them to a smaller city, sometimes planned or others made into forward capitals (biggest city in the nation, and transport, cultural, and industrial hub), like Rio de Janerio was for Brazil (pre-1960), Lagos for Nigeria (pre-1991), Dar es Salaam for Tanzania (pre-1974, and officially in 1996), Karachi for Pakistan (pre-1960s), Istanbul/Constantinople for the Ottoman Empire and later on the Republic of Turkey (pre-1923) or Rangoon/Yangoon for Burma/Myanmar (pre-2006).
Countries (and in this case states) move their capitals for geographic positions, and to make themselves seem equal to all people, instead of focusing towards one select region, the sea, or allocating resources on a specifically smaller city (in the case of Karachi - Islamabad, or Rio de Janerio - Brasilia, Istanbul/Constantinople - Ankara or Lagos - Abuja). Those cases would've caused some internal strife or a case of favoritism.
My source (in terms of NYC-Albany capital change): Corey, Albert B. “How Albany Became the Capital of the State”
Holston, James. "The Modernist City: An Anthropological Critique of Brasilia" (Some tidbits on Rio-Brasilia capital change, and it was anticipated for years prior than the late 1950s).
The US state of Illinois has an interesting history relating to its three historical capitals. When it became a state in 1818, Kaskaskia was named the Capital. Kaskaskia is on the Mississippi River and was a major settlement and administrative center at the time.
In 1819-20, land speculators succeeded in getting the capital moved to Vandalia, which is more centrally located in the state, but in the middle of nowhere at the time. Kaskaskia became a virtual backwater and then literally so as the Mississippi changed course in 1881 making the town on an island and eventually eroding much of the site away. Today, Kaskaskia is the second smallest incorporated community in Illinois with a population of 14. It population is estimated to have peaked at around 7,000 in the 18th century.
In 1837, Abraham Lincoln, then a member of the Illinois assembly, and eight colleagues (called the "Long Nine" because their cumulative height was 54 feet or an average of six feet each, evidently tall for the period) proposed a bill to move the capital to Springfield in Sangamon County. The bill passed and the capital was moved by 1840 (despite the Vandalia contingent building a new brick state capitol building in an effort to thwart the move). Springfield is centrally located and about equally easy to reach from all corners of the state.
Today Chicago is by far the biggest city in the state (2.7 million) and the third largest city in the US, but Springfield, population 117,000 remains the state's capital (it is the state's sixth largest city, eclipsed by Chicago, Rockford, Aurora, Joliet, and Naperville). I cannot find evidence that Illinoisans ever seriously considered moving the state capital to Chicago. Some have suggested this move, however, (http://www.stltoday.com/news/local/columns/pat-gauen/illinois-corruption-explained-the-capital-is-too-far-from-chicago/article_c38d21b7-0134-5124-b56f-3bc99a60c327.html) as a means to reduce perceived corruption in the Illinois Statehouse. Chicago had a population of about 200 in 1833, but was incorporated in 1837 and for several decades was the fastest growing city in the world, eventually reaching a population of 4,000 by 1840, 90,000 by 1857, and 1.7 million by 1900.
Hi there, I think there are two elements to this. The first is that a lot of states weren't admitted to the Union until after significant development had taken place there. Because of the structure of the Senate, where each state gets two seats independent of population, adding a new State (especially if it has a very small population) has the possibility to change the balance of political power significantly.
This was particularly important in the first half of the 19th century when there was a lot of tension between "slave states" and "free-states". There was a perfect balance in the senate between these two forces and the Missouri Compromise was put in place to keep it that way. The "Compromise" (I would call it an appeasement policy, but that's a different topic) said basically that States would be admitted to the Union in pairs, one "free-state" and one "slave-state" in order not to throw the Senate out of balance.
So if we take other contributor's, like /u/LifeMadeSimple, idea that often these choices in where to place capitals were compromises between already existing population centres this makes sense.
This contrasts with Canada where new provinces were usually founded (I'm looking at you Alberta, Manitoba, Saskatchewan) and then (white) people were encouraged to come and settle. When they did come, they settled near the railroad and near cities where they could sell/buy what they needed. Remember there was really only one railroad (CPR) and if you got away from it you were basically cut-off from the rest of the nation. The Canadian federal government doesn't have much of a disincentive to not found new provinces as even the Senate has some population correlation although less than the House of Commons and is appointed. (so perhaps there's even an incentive to get to be the PM who appoints new Senators)
So there would be very small populations in general when Provinces were founded (I'm mostly addressing post Confederation additions) it was easier to give people a place to move to. In other words, why would you spread out if you could live close to markets, political influence and transport?
I'm drawing from three books for this:
The Missouri Compromise and Its Aftermath by Robert Pierce Forbes
and
The Great Railway (both 1871-1881 and 1881-1885) by Pierre Berton
Historically interesting? Let's talk about The Great State.
In Texas the first capital with any kind of permanence was established in Houston by the first president of The Republic of Texas, Sam Houston. The similarity in name is not coincidental as the city was literally named after Sam Houston.
Unfortunately for Sam the republic had term limits and when his was up one of the presidential hopefuls was a fellow who didn't care for either Houston, Mr. Mirabeau B. Lamar. One of the planks in Lamar's election campaign was to move the capital to Central Texas. His stated reason was a more centrally located capital. Texas was about 389,000 sq miles in size at this time so that was a pretty good reason. Of course there was a little problem with the Native tribes that were still living in most of the western part of Texas at the time. Lamar had a solution for that as another plank of his campaign was to drive the Cherokee and Comanche tribes out of Texas even if they had to be destroyed.
Lamar may also have had issues with the city of Houston as it had things like Malaria and Yellow Fever outbreaks at the time and was infamous for drunkenness and prostitution. As if to prove the dangers of Houston, one of Lamar's opponents in the race for president, James Collinsworth, drowned in Galveston Bay during the race. He was allegedly on a seven day bender and drunkenly fell in.
In any case Lamar's other opponent Peter W. Grayson killed himself and President Lamar fulfilled his promise to move the capital to Central Texas by relocating it to a town named Waterloo which was later renamed to Austin after the most famous real estate developer in Texas history Stephen F Austin.
Later Sam Houston would be president again and this thing called the Archives War would happen when Houston would attempt to move the government back to Houston after Mexican troops captured San Antonio. Austin patriots(?) would use a cannon to keep Rangers from moving the national archives out of Austin. Anyway two years later when Texas was annexed the capital was permanently fixed in Austin.
/u/LifeMadeSimple has provided a good account of Connecticut, so I'll cover New England at large with some extra detail for Massachusetts, since that's my field.
The current territories of the New England States (ok, ok States and the lovely Commonwealth...which is just semantic difference) were not so rigidly defined in the early years of settlement through to the late 1860s in the case of the border of Rhode Island and Massachusetts. The Plymouth Colony, the Massachusetts Bay Colony, the Saybrook Colony, the (Connecticut) River Colony, the New Haven Colony, the non-theocratic Rhode Island plantations, and the Province of New Hampshire all contained varying amounts of a territorial-defined civil political structure. There were also failed English-led colonization attempts by the Dorchester Company and Popham settlement, failed Colony-led expansions, failed Colony-led settlements (fx. the attempt of New Haven colonists to establish a Puritan outpost in New Jersey), and successful Colony-led expansions that later changed hands: the Plymouth Colony had a trading post in present-day Maine; Cape Ann (historically: "Anne") hosted temporary English fishing factories, seasonal settlement by the Plymouth Colony, settlement by Dorchester Company men, and finally incorporation into the Massachusetts Bay Colony.
There's a lot more to say about this period (particularly how English action in the later 1600s 'defined' the modern states). However for the purposes of the question, the major theme is this: "regions" - areas linked socially and economically - were an important determinant and influence in crafting more rigid boundaries. Most "regions" had a central settlement, but not all regions were contained within one political entity. As /u/LifeMadeSimple mentioned, "Connecticut" hosted two (three if you count the short period when the Saybrook and River Colonies were separate) major political structures, but about 3 to 4 separate regions (personal, not academic, view): the Connecticut River which encompassed Hartford and also the Baymen-led settlements at Springfield, the New Haven Sphere, the central/southeastern coast that was closely aligned with similar littoral towns in southern RI and Long Island, and the "or 4" region in Northeast Connecticut that was initially sparsely inhabited by Europeans, but those that did settle there were generally early Scotch-Irish immigrants, outcasts from surrounding colonial theocracies and espoused that flinty, don't bother me, Swamp Yankee mentality.
Why is that important in understanding the placement of a Capitol? Well, each "region" had social connections that centered on a major settlement that was explicitly distinct from the nominal capital of whatever political entity that happened to maintain (very often, arbitary) control. But therein lies the point; "regions" might have wielded substantial populations and economic influence, but all that mattered was the level of both within the "official" entity that encompassed a region. In New England there are 3 major typologies:
After the Rev. War, New Hampshire - like many States in the 19th century - sought a centrally-positioned capital, different from former (semi-)official capitals in the southern part of the State as a sort of symbolic presence within it's territory which was primarily mountainous, but the majority of whose population lived by the coast and practiced an economy similar to that of Massachusetts (with whom New Hampshire did not then and does not now have a..."great"...relationship). Vermont (it's history is really a whole 'nother story) and Maine followed the practice of New Hampshire in establishing centrally-located capitals that were removed from the major centers of population and economy and were not the "colonial"-era capitals of either state.
Connecticut, with it's distinct regions, is a bit harder to sort through. Hartford was one of the two major historical settlements on the River (the other being Springfield, MA), but it (as mentioned) it is more central and, probably most importantly, farther removed from New York which was absolutely not within the sphere of Yankee-settled lands, despite that fact that the historical "region" centered on Hartford was not dominant in CT as it was split between CT and MA - New Haven and the southwestern towns were the major agglomerations with the southeastern littoral towns proving a third, probably anti-proximity-of-capital to New York State role.
Massachusetts and Rhode Island are anomalous to a certain extent, but understandably so. The Massachusetts Bay Colony was settled far more rapidly and far more densely than any other European colony in North America. Though settlers did spread into the interior, in the 1600s, the "Massachusetts Bay Colony" essentially described modern-day Middlesex, Suffolk, Essex, and parts of Norfolk (there is another, historical "Norfolk County" in MA but I mean the modern iteration) With such a relatively dense-network of settlements, there was an immediate need for organizing both some sort of hierarchical political structure which was centered on Boston. This doesn't mean Boston predominated at all - in fact as late as 1790, the population of Salem, Beverly, and Marblehead was 75% that of Boston. Most political affairs were directed by the towns themselves, but Boston did serve of the established location for handling colony-wide business. It also developed from the mid 1600s onwards as the principal port of the early US, only being marginally surpassed by Philly and NYC in the mid-1700s, but with a late yet substantial surge from 1785-early 19th century under the Viriginia Dynasty. Massachusetts was unique in that it's official political borders were more closely aligned with it's "regional" borders than any other state save for Rhode Island. The Plymouth and Connecticut River settlements never achieved any where near the importance of Boston in early Massachusetts, thus making Boston (or a town close to Boston) the only realistic choice for a capital.
Rhode Island, like Massachusetts Bay, was the most densely-populated Colony and later State for the entirety of its existence up to the 20th century when it was surpassed by New Jersey. RI is still number two though (MA is three). The Colony itself was founded as a refuge for religious dissidents from the hardline puritan-controlled entities, but it's initial settlers didn't necessarily get along with each other either. Providence was the first major settlement, but Newport was the most populated and economically significant. Newport was, however, known at the time for its pretty virulent political factionalism and disagreements with other towns on Narragansett Bay, which more or less preserved Providence as the capital well before it became an industrial powerhouse.
There is also a connection to nearby states. Upstate New York, for example, was settled almost entirely by rural New Englanders (as were parts of Pennsylvania, Ohio, and Michigan), who held a distinct animosity towards their free-wheeling, libidinous, urban, Dutch-inflected down-state compatriots. In this, they were joined by settlers on the middle and eastern stretches of Long Island which was also settled by Yankees. Those two groups more or less guaranteed that New York City would not become the capital. Pennsylvania had a similar experience with it's population split amongst Scotch-Irish in the west and Germans and Quakers in the east.
So, I hope that gives somewhat of an answer about why States even sought to establish "centralized" capitals, often as a counterweight to the dominant political region.
/u/discovering_NYC posted a fascinating answer a few months ago regarding why Albany is the capital of New York and not New York City that may be of interest:
https://www.reddit.com/r/AskHistorians/comments/3mitxa/why_isnt_nyc_the_capital_of_new_york/
I really don't think this is a good comparison. There are only 10 provinces from which to draw examples from, while the US has 50. 10 is just not a large enough sample to make a comparison.
Out of the 50 US capitals, the following are the second largest cities in their states: Honolulu, Boise, Phoenix, Salt Lake City, Denver, Cheyenne, Oklahoma City, Des Moines, Little Rock, Jackson, Indianapolis, Columbus, Atlanta, Charleston (WV), Columbia (SC), Boston, Providence
Out of the 50 US capitals, the following are the second largest cities in their states: Lincoln, Bismark, St. Paul, Baton Rouge, Nashville, Madison, Montgomery, Raleigh, Dover.
Out of the 50 US capitals, the following are the third largest cities in their states: Juneau, Salem, Concord.
The others are Sacramento, 6th; Olympia, 24th; Carson City, 10th; Helena, 7th; Santa Fe, 4th; Austin, 4th; Topeka, 5th; Pierre, 8th; Springfield, 6th; Jefferson City, 15th; Frankfurt, 14th; Lansing, 5th; Tallahassee, 7th; Richmond, 4th; Annapolis, 7th; Harrisburg, 10th; Trenton, 10th; Albany, 6th; Hartford, 4th; Montpelier, 5th; August, 9th.
Over alf of state capitals (26) are the largest or second largest city in the state. Out of Canada's small sample size of 10, only two capitals are not in the top 2 cities for population, Victoria, and Fredericton. But, to me, it's just not a big enough sample size.
I know for South Carolina it was originally Charleston, then the economic and political heart of the state and most populous city. It was one of the most populous in America. Though the people in the upstate hated that is was there since it took over a day to travel there from the upstate back then. They petitioned a lto move the capital to some where more central. In 1786 it was moved to Columbia, then a small little outpost. The legislature first met there in 1790. Since then Columbia has become the most populous and the economic heart of the state. (Though it is losing ground to Greenville)
Texas has a very interesting history regarding its capital, with much of the timeframe prior to statehood having its lands governed by seats of power in present-day Mexico, specifically Coahuila. After defeating Mexico and gaining its independence, Texas became its own nation in 1836.
During the ten year timeframe in which Texas was its own country, its capital moved around quite a bit, centering in present day southeast Texas - Washington-on-the-Brazos (present day Washington County outside of Navasota), Harrisburg (present day Houston), Velasco (present day Brazosport), Galveston Island, West Columbia (southwest of Houston), Houston (again) and finally a move to the Hill Country and Austin - which at the time was called Waterloo and was renamed to honor Stephen F. Austin. The final location was chosen by an official capital search committee. However, before it was out of its infancy, Sam Houston returned the seat of government to Houston for a third time due to threats from the Mexican Army renegades located in the San Antonio area, south of Austin. It returned to Austin in 1844, and has remained there ever since.
Thus, in the ten years Texas was a nation, it had six capitals. However, by the time it became the 28th state in 1845, the capital had taken root in Austin where it remains today. I always find it funny that Houston had the capital three separate times, but could not retain it. Any Texan can tell you - that's how it goes regarding Houston. It's a fantastic place with so much to offer, yet sometimes it just gets no respect!
Tallahassee, Florida, was originally chosen for geographic and logistical reasons.
Spanish Florida historically comprised two distinct settled regions. East Florida, with its administrative center at St. Augustine (the oldest European settlement in North America), had most of its European settlement along the Atlantic coast; West Florida, with its administrative center at Pensacola, comprised a settled swath of land along the Gulf Coast. Between them was what is now the Florida Panhandle, largely unsettled because its hilly, sandy interior wasn't particularly desirable for agriculture and because of the presence of sometimes-hostile Apalachee natives, and the coast turns from beaches and good natural harbors to mangrove swamps east of the Apalachicola River. This division was formalized under British rule during the Napoleonic Wars, and after the territory was returned to Spain, Spain continued administering them as two separate territories with two separate administrative centers.
After Spain ceded the Floridas to the US in the Adams-Onis Treaty, the US organized the region as one singular Florida Territory (detaching a large chunk of West Florida to assign to Louisiana, Mississippi, and Alabama). When Florida was made a state in 1822, the legislature initially tried to split its activities between Pensacola and St. Augustine. The first session was held in Pensacola, and the St. Augustine delegation duly traveled two months by sea to attend; the second session was held in St. Augustine, with the Pensacola delegation traveling rough overland for almost a month. The delegations agreed to establish a capital halfway between the two cities to cut travel time, and chose the abandoned Apalachee village of Tallahassee as a location about halfway between the two main cities.
Tallahassee itself has an interesting history; the Marqis de Lafayette was granted a large tract of land nearby, which he attempted to encourage French settlement upon. One of the few settlers to take him up on the offer was Achille Murat, deposed Crown Prince of Naples, son of famed French general Joachim Murat and cousin to Napoleon Bonaparte. Prince Achille was chosen as one of Tallahassee's first aldermen in 1824, then elected mayor the following year. Certainly not what you'd expect from a podunk third-rate city in the less fashionable part of Florida!
I don't know if I should post a new thread for this, but I am from Oregon and I live in California right now. I would like to know why Salem, Olympia, and Sacramento became our west coast state capitols. None of these cities really grew a lot. Sacramento is arguably a decent sized city compared to the latter two, but there are far bigger cities in the PNW that have continued to grow very large through the 20th and 21st centuries.
Salem in particular is a head scratcher for me, there is really not a lot there. Why wouldn't these cities grow because they are state capitols?
In Washington State the Capitol is Olympia because of power struggles between Tacoma and Seattle.
I can't say for every State, but in my home state of Kansas, Topeka became the capital for a couple reasons. First, the previous capital was raided and burnt, so a new capital was needed. Second, it is (or was by the era's standards) in a strategically advantageous place. Kansas had the unfortunate history of suffering attacks from natives during the westward expansion, and lots of civil war related violence. It was during one of these instances. The partisan ranger act of the Confederate States basically put bounties on places and encouraged Confederate sympathizers to go raid and stuff. Quantrills massacre at Lawrence is probably the best known, and certainly the largest instance of the Partisan Rangers. But all along the borders violence rang out. Kansas and Missouri both got pretty messed up from it.
Anyway the capital was moved to Topeka because it would be difficult to raid before a defense force would be able to get set up.
A similar question could be asked about National Capitols. Why is Ottawa the Capital and not another major city such at Toronto? DC rather than, say Chicago? Or, for other youngish new world countries, such as Canberra or Wellington. And let's not even look at Sth Africa which has 3 Capitals... And don't get me started on Brasilia.
In each case, they each have unique historical reasons, each to do with either being the first city founded by settlers, solving rivalries between competing cities, and/or a desire to make the Capitol centrally located in times when communication and transport was slow.