Because of the War of 1812, James Madison followed in Washington's steps and advocated economic nationalism. The War in his eyes showed that there is a need for a stronger federal government and that US had to have stronger military and better economy. That is why his presidency was a nationalist one and not focused on the individual rights of the states.
The main way in which anthropologists are able to make generalizations about human behavior is by looking at how they used to live their life--their tools, migration patters, war tactics, etc--which are very similar throughout populations.
