Answer:
The Compromise of 1850 was an agreement between the North and South states of the United States.
Since the independence of the United States in 1776 and until the Compromise, the slave states had dominated American politics, not least thanks to the three-fifths clause. But when President Zachary Taylor in 1849-50 made proposals to incorporate the state of California, which, because of the gold fever, grew at tremendous speed, the balance of power changed. Presumably Taylor, who himself was a slave owner, had expected California to become a slave state, but fearing that the presence of slaves in the state would undermine the white gold digging, thus depriving them of their existence, they opposed the slave trade and expressed their desire to become a free state. The compromise was that California was recognized as a free state, while the territories of Utah and New Mexico could later be admitted as either free or slave states.
The free states now constituted the population majority, thus dominating the House of Representatives, which markedly changed the political balance in the years leading up to the Civil War.