Florida
Louisiana Territory was purchased in 1803. Florida Territory was purchased in 1821, California, New Mexico and Arizona Territory followed with the Mexican American War. Alaska in 1867.
France
They purchased it from France.
ALASKA.
Spain
In 1846 Britain agreed for the US to take control of the territory
In 1898 by Act of Congress.
In 1898 as a Territory by Act of Congress.
the US gained Florida territory by threatening to police the territory so the Spanish gave it to them.
American Samoa.
He did indeed- paid 15 million dollars for this territory in 1803.