- Abraham Lincoln: the first anti-slavery president; his election caused the South to secede
- Antonio Lopez deSanta Ana: Mexican general at the Alamo; later the president of Mexico
- Dred Scot v. Sanford: "a black man has no rights a white man is bound to respect"
- Franklin Pierce: 14th president of the US; favored the Kansas-Nebraska Act
- Frederick Douglass: escaped slave; one the most powerful antislavery speakers and writers
- James K Polk: elected president in 1844; gained WA, OR, CA, NV, TX, NM, AZ, and NV for the US
- John C Freemont: army commander who captured Mexican California for the US
- John L O'Sullivan: coined the term "manifest destiny"
- John Sloat: led the US Navy in capturing Monterey, CA
- Kansas-Nebraska Act: the settlers of KS were allowed to choose whether to be slave or free; this was a very bad idea
- Know Nothings: the American Party; anti-immigrant and anti-Catholic
- Ostend Manifesto: secret plan to take Cuba from Spain
- Republican Party: the antislavery party; made of antislavery Whigs and northern Democrats
- Sam Houston: won independence for Texas at the battle of San Jacinto
- Stephen Douglas: created the Kansas-Nebraska Act; lost the election of 1860 to Lincoln
- Steven Austin: the "father of Texas"; tried to find a peaceful settlement to Texas' conflict with Mexico
- Texas Annexation: After the Battle of San Jacinto, the US took almost ten years to decide to make Texas part of the Union
- The Compromise of 1850: With CA ready to become a free state, the Fugitive Slave Act was strengthened
- The Gold Rush: After its discovery in 1948, 10's of thousands of treasure hunters descended on California
- Thomas O Larkin: Leader of American interests in California; helped take Monterey and later Southern CA
- Treaty of Guadelupe Hidalgo: ended the Mexican-American War; gave the US lots of territory for only $15million
- Zachary Taylor: American general; invaded northern Mexico; later elected president