higher granularity than just country-level.

per capita is usually the way to go but in this case it might be strange as the populations have changed a ton over the years.

Also, you can pretty clearly draw conclusions from the graph already, like judging which proportion of US residents since 1850 were born where. Per capita numbers would just obfuscate

not quite, which makes things interesting. Florida's pretty low while Iowa's much higher than I expected. It's interesting to speculate about which states people go to and which they move from. I only hear stories of people going from rural states/areas to the coasts/cities but not the reverse and I think that plays out a little on this map.

Wouldn't expect there to be much of a difference. Computers really outpace humans when it comes to tactical calculations which wouldn't really show up on this.

The only important thing I got was that humans stick to the "control the center" principle a little too strongly