Around AD 1300-1400, various Uto-Aztecan-speaking groups ("chichimecas") migrated south from what's now the western United States. Some of these groups travelled as far south as the Valley of Mexico, where they assimilated into the local culture and eventually rose to dominate the region via the Aztec Empire. Around the same time, but a bit to the east, the Mississippian cultures experienced some sort of partial collapse, as evidenced by the abandonment of their metropolis, Cahokia. I would be curious to know if that there is any evidence that these events were related.

For instance, could the collapse of the society centered around Cahokia have caused political chaos that the proto-Nahua fled from? Or could the proto-Nahua have occupied some sort of economic position in Missippian society which they lost in its collapse, sending them south towards greener pastures?

(paging /u/400-rabbits, /u/Mictlantecuhtli, /u/reedstilt)

Why was the US so suspicious of the soviet union as to not let them in on the manhattan project but had a british mission at los alamos/quebec agreement/etc?

The hatred can't because of someone like klaus fuchs since israel routinely stole/spied on US without any damage to their relationship.

Why did the US view communism as such a major threat?

How could you possibly keep it cold enough to be safe?

e.g. are some roman aquaducts still used for their original purpose? Wells that have been in use since antiquity, etc.

I've been watching a lot of WW2 documentaries and it's just something I picked up on (and it's something you do see quite a bit with modern politicians)... I thought he didn't practice his speeches and made them up as he went along...

We all know what happened in Pompeii but how did the public react to the news and is there any evidence of a response issued by the leaders of the Empire to the public like you would in modern day?

Just something that struck me today as you never hear about the reaction to it.

We know about Marco Polo and other european traders and missionaries going to China, but was there anything like that in the reverse? I'm looking at the historical period from the fall of the Western Roman Empire to the 1500s.

For example, would there have been Chinese mercenaries in Byzantium akin to the Varangians? Would there have been a 'Chinese quarter' in Byzantium much like the Latin Quarter? Would there have been Chinese traders in Byzantium or medieval Venice or Florence or Rome or Kiev?

My late grandfather passed on the family tree to me, included in everything is a WW1 war journal, leather bound notebook and original pencil, both belonged to my great-great uncle who was killed on the western front, and family portraits from before he went to war.

The journal is in amazing condition, he kept a detailed log of his movements up until his death.
The notebook is slightly worn but still great condition for 98 years old.
I don't know how I should be storing these to maintain the condition. Right now they're in a plastic folder...

When did a culture of fine dining in the west develop?

All I've been able to pull up in a google search is "The Reckless Decade," but Publisher's Weekly says it covers labor strife, slum life, the robber barons, and the Spanish-American War but not much else. I'd really like something, well researched of course, that gives a wide angle view of the US in the 1890s. Not just the history of the Progressive Movement or Populism, etc.

This was the time before it was common knowledge that smoking was unhealthy so why did people discouraged children from smoking?

The east India trading company had enough men under weapons to effectively be called an army, is there any earlier times where something simelar ahs happend? And has there been anything since?

I've been doing some research and it seems that for quite a while de Valera was vilified in the eyes of Irish historians. I read that recently perception is changing on de Valera. Does anyone know why and to what extent this seems to be changing?

And what technological advantages did his ships have over ones in earlier centuries?

I know the Vikings made it earlier, but those distances are shorter and not as far over open ocean.

Why are there still officers and enlisted in modern militaries, as opposed to just one rank hierarchy? I'm guessing the origin of the system goes back to knights and feudal times (maybe?), and anecdotally I've heard that before everyone was literate, officers read orders aloud to their men. I'm in a U.S. officer accession program, and from what I've experienced, the distinction in practice is just one of class -- who can afford to go to college, etc.

I just noticed that they seemed to be at roughly the same time, and the Puebloans had some kind of uptick in violence that pushed them south. Was wondering if maybe there was some kind of connection.

It looks like Ben Franklin and maybe Thomas Jefferson have their real hair, but everybody else is pretty bald and wearing a wig. What's the deal?

I've read of the conquests and extermination of the Khwarazmian or of Baghdad, and millions were killed and bodies piled up like mountains (or small hills).

I've also read, forgot where, how it would gleam a bright white in distance like a white hill until they got close and saw they were bones.

Bones last for quite a long time. Have we found any of these mass burial sites?