IT IS PROBABLY THOMAS EDISON
IDK I tried
Britain wanted to become less involved in the government of their colonies because it was very time-consuming and expensive. It was time for the colonies to become more independent.
There was a lot of patriotism after 1812. It was essentially the second revolutionary war.
The US actually gained territory in the south (West Florida from Spanish).
Manufacturing grew during this time to supply the war effort.
A ton of natives were killed during the war (10000 according to wikipedia), so there was a lot less resistance from the natives.
The correct answers are 1, 2, and 4.
A shift in the population demography, especially along the West Coast.