My answer is Louisiana purchase.
Germnay, italy, and japan were known as the axis powers
In 1854, the controversial Kansas-Nebraska Act, split two
existing political parties the Whig party and Jacksonian Democrats and led to
the creation of the Republican party. Kansas-Nebraska act overturned the Missouri
compromise and allowed settlers to decide whether slavery would be allowed in
their state. This led to the creation of the Republican party founded by anti-slavers
whose primary objective was fighting slavery.