I love questions about Africa because I think many responses that talk about it's current condition don't address the large amount of influence colonization played in changing the fabric of a nation. "The Scramble for Africa" vastly undermined the African nations. Contrary to popular opinion Africa was growing economically before its occupation. African countries used resources to trade and connect with other groups within Africa and other continents. However, when the Europeans arrived their goal was not only to profit and take resources but to reduce the power many African leaders had over their territory and goods, "The British, in their zeal to extirpate the slavers and to protect their own legitimate commerce, were driven to intervene in local politics on a scale which no European power had ever done before". This also played into the mindset of imperialism: enrich the mother country at all costs. The Europeans had access to cheap goods and now cheap labor , and had no reason to build infrastructure(or even keep the infrastructure already in place in tact), or give a substantial education to the people. Fast forward a few years and you now have a country with no well maintained infrastructure, a largely uneducated populace, and vast differences between countrymen. Although Africa has unique problems of its own: its cultural diversity. Africa was largely split into many tribes and ethnic groups that loosely identified with each other ,while exceptions exist, by and large many African countries weren't countries in the traditional sense of the word. After colonization many countries were forced to become one, with members with different languages and different religions, only because the countries that pillaged them required them to. Ethnic wars, and fighting has become a main stay of Africa's history. Time also plays a factor-- many African countries have just relatively recently began governing themselves and many of these efforts may or may not change in the years to come, heck countries themselves may change. I hope that answered your question, I rattled off an answer as quickly as I could. Sources: http://trace.tennessee.edu/cgi/viewcontent.cgi?article=1182&context=utk_chanhonoproj

I can't speak for Africa as a whole as it's a huge place, but I am familiar with German colonialism in Africa.

Togo, located in West Africa, had already been devastated by centuries of slavery from both Europeans and other African nations. Millions of Togolese had been removed from the area and shipped off to the Americas to die laboring. As the Atlantic Slave Trade ended the region grew to enjoy some limited prosperity in the second half of the 19th century. Palm oil became a hot commodity on the world market as an alternative to whale oil, and Togo had lots of it. Western merchants were present in Togo, but they did not control the land or people, only trading with the Togolese people who became prosperous as a result. Palm oil was unique in that it mostly grew along the coast line where nobody controlled or owned the land, so it provided a sort of unregulated industry immune to any attempts at control.

Before I start talking about the Scramble as it relates to Togo, it's important to realize how Togolese society was different than how it was during and post colonialism. The Togo had their own native religions as well as Islam. The people of Togo were a very diverse group of people with dozens of ethnic identities, and no nation state which controlled the population. Togolese women generally controlled the majority of the wealth and land in their society due to a complex system of gift giving, gendered divisions of labor, family dwellings and arrangements, and polygamy.

The Togolese also practiced a uniquely African form of farming called mixed cultivation where three or four different crops were grown mixed together in a single field. Beasts of labor could not tolerate the weather well and the African diseases, so all farming had to be done by hand. As a result of crop harvesting being done by hand it would appear chaotic, unordered, appearing not unlike an overgrown field to a western farmer. The mixed use was highly efficient for mixing sustenance based farming and some market crops together in harsh conditions where it would have been impossible otherwise. For example, by allowing cotton to grow in the shade of maize it would grow through the harsh sun. The cotton would not blossom until the maize was harvested, at which point it would be quite hardy and not require the labor intensive chopping back as it did in the American South.

German colonialists who came into the region at the closing of the 19th century found a land and people that did not fit with their view of how things were done. Women had far too much power, the people weren't Christian, their farming methods were absurd, and they were difficult to control or understand with so many varying languages, ethnicity, and religions.

One of the first things they did once military control was established in the coastal regions was to attempt to amalgamate the Togolese peoples. They created an ethnicity called Ewe that wove together the many differing mythologies and stories from the differing groups of people in Togo, and encouraged people to only speak a single language (The name of which escapes me at the moment.) This created a group of people that is more easily grasped by an outsider. No longer do you have to learn many customs and languages to control a group, you only need learn one, and it happens to be one you personally cultivated to encourage domestication and dependency among the people. German overlords also begin discouraging the teaching of English, and actively belittle any African who becomes prosperous as a "Dandy". Where traders once treated the Togolese merchants as relative equals, now they were called "Negro" and much worse, and treated as sub human.

Secondly the native economy of Togo was obliterated. Property ownership laws, marriage laws, and farming regulations were all changed to suit the German overlords. The techniques for mixed cultivation are, as far as I know, a lost art now. The Togo people were made to be economically dependent on the German merchants and military. The entire Togo region's economy was altered to produce industrial raw cotton for processing elsewhere. Raw cotton was not a terribly profitable product at this point because the American South produced the majority of it at low prices. India might have started producing a lot as well at this point but I am not as familiar with that. That didn't matter to the Germans, they wanted the cotton and they didn't want to pay America or Great Britain for it. Many Togolese merchants were forced to buy seeds and supplies from German merchants and to use western farming methods which were wholly unsuited for the Togo environment. Togo farmers were forced to buy crop varieties that either would not prosper or were difficult to grow, and to use animals which would die in vast numbers. Now the Togolese are no longer growing their own food.

Togo's economy is totally dependent on their overlords. Togo's native culture, languages, and religion are suppressed and today mostly unknown or forgotten. Lest you think the Togolese need to simply rise up against their masters, think again. Any violence would be met with the utmost brutality. The German military answered only to the Chancellor, there was no civilian oversight like in British colonies. German officers were feared for taking trophies of war including heads and other body parts. Whole populations could be wiped out like the German's did with the Herero in Namibia (worthy of it's own post), in what is probably the world's first Genocide.

To put it shortly, Germany destroyed everything about Togo and replaced it with a cheap facade of what they thought it should look like: easily controlled, domesticated, homogenized, and totally dependent. After the Germans lost the colony the various nationalities began to reassemble themselves to some degree and wish for autonomy, which leads to many problems in other African nations today, in addition to their terrible economy's.

Sources

Primarily Alabama in Africa by Andrew Zimmerman and Absolute Destruction by Isabel Hull.

Also worth reading if you want to know more The Rulers of German Africa 1884-1914 by Peter Duigan and H. L. Gann, and The Kaiser's Holocaust by Casper Erichsen and David Olusoga.