The louisiana purchase

nearly tripled the size of the united states.

improved relations between the united states and britain.

set the border between the united states and canada at the forty-ninth parallel.

nearly doubled the size of the united states.

The correct answer is nearly doubled the size of the United States.

The Louisiana Purchase was bought by president Thomas Jefferson in 1803 from the French. This resulted in the United States gaining roughly 800,00 square miles of territory, essentially doubling the size of the United States. This purchase was a huge step forward in American expansion, as this territory would eventually turn into part of at least 13 different US states in the future.

cuban communists pressured the soviet union to place missiles in cuba.

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.