Popular Sovereignty: A doctrine asserting that people should have the right to rule themselves. This idea proposed that residents of U.S territories should have the right to decide whether they want to enter Union as free or slave state.
Wilmot Proviso: Proposed an American law which aimed at banning slavery in any territory acquired from Mexico following War with Mexico.
Compromise of 1850: Package of five separate bills passed by Congress which defused confrontation between slave and free states on status of territories acquired during Mexican-American War.