By supporting the Monroe doctrine, U.S leaders:

the puritans were a group of people who grew discontent in the church of england the common unity strengthened the community.

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.