A theme is a history surrounding it or a repeating moment, a period is a time that the themes were set in. hope this helps P
The Treaty of Paris was signed by the U.S and Spain. After the treaty was ratified, the U.S became an imperial power. The U.S gained Puerto Rico, Guam, and the Philippines from the treaty.
I think it was because of the weather in winter the Indians would migrate. I think that's the answer.
