The US gained Alaska in 1867.
it was the indians
The Mexican American War.
the US gained Florida territory by threatening to police the territory so the Spanish gave it to them.
The US gained control of the Utah Territory based on the treaty with Mexico that ended the Mexican War
American Samoa and the US Virgin Islands.
War or some kind of battle
True, Guam became a US Territory as a result of the Spanish American War.
Oregon
I think it was Hawaii.
It gained California and the American Southwest.
The Oregon territory was gained by the UNITED STATES of AMERICA from Britain. The Oregon territory was fairly large, which enabled the US to gain more resources and have more land for settlement. THESE FACTORS ARE THE EFFECTS OF THE ACQUISITION OF THE OREGON TERRITORY