Mexican-American War
     -Wilmot Proviso

Election of 1848
     -Zachary Taylor   (Whig)
     -Lewis Cass   (Democrat)
          -Popular Sovereignty

Compromise of 1850
     -Henry Clay
          -Fugitive Slave Law of 1850
     -John C. Calhoun
          -Disquisition on Government (1850)

Kansas-Nebraska Act (1854)
     -Stephen A. Douglas
          -Popular Sovereignty
     -Republican Party (1854)

Dred Scott v. Sandford (1857)

John Brown's Raid (1859)

Dual Crises of the South
     -External
     -Internal

Political Parties, 1860