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