| c. 10,000 B.C. | The first Americans began to migrate to North America from Asia. |
| 1510 | De Montalvo's novel, Las Sergas de Esplandian, published
in Spain. |
| 1521 | Cortés conquers the Aztecs, and Spain controls Mexico. |
| 1674 | Sanson Map outlining the Island of California published. |
| 1769 | Junipero Serra and de Portola's expedition begins to colonize Upper
California. |
| 1769-70 | Presidios and missions are established at Monterey and San Diego. |
| 1776 | San José pueblo is established. |
| 1776 | Mission is established in San Francisco. |
| 1781 | Los Angeles pueblo is established. |
| 1821 | Mexico gains its independence from Spain and takes control of California.
|
| 1826 | Jedediah Strong Smith makes the first overland trip by an American to California from the East. |
| Early 1830s | Americans settle Oregon. |
| 1835 | Texas becomes a republic. |
| 1844 | "54°40' or Fight"; Polk, favoring expansion, is elected
president. |
| 1845 | John O'Sullivan, editor of the United States Magazine and Democratic Review, coins the term Manifest Destiny. |
| 1846 | Oregon ceded by Great Britain to the United States. |
| 1846 | Bear Flag Republic, Sonoma, California.
1846 Mexican-American War begins. |
| 1846 | Mormons sail to and land in San Francisco, led by Sam Brannan in
defiance of Brigham Young. |
| Jan. 24, 1848 | Gold is discovered at Sutter's Mill. |
| Feb. 2, 1848 | Mexican-American War ends with the Treaty of Guadalupe
Hidalgo. |
| 1849 | California Gold Rush begins on a global scale; the world rushes
in. |
| Sept. 5, 1850 | Compromise of 1850; California becomes a state. |