Mexican-American War: A war between Mexico and the U.S from 1846 to 1848. The U.S won and gained new territories. It's like a sports match where the winner gets to take home some of the loser's gear.
Compromise of 1850: This was a package of five separate bills passed by Congress in an attempt to resolve disputes over slavery in new territories. Think of it as a group project compromise, where everyone gives up something to reach an agreement.
Popular Sovereignty: This principle allowed settlers in a territory to decide whether slavery would be allowed within their region’s borders. Imagine it as letting your classmates vote on whether or not homework should be assigned over the weekend.