Mexican Cession: The Seven Territories Acquired by the U.S. in 1848

The Treaty of Guadalupe Hidalgo (1848), ending the Mexican–American War, transferred a vast territory from Mexico to the United States. This "Mexican Cession" comprised lands that became all or part of seven present-day states:

The Seven Ceded Areas

1. California – Entire present-day state
2. Nevada – Entire present-day state
3. Utah – Entire present-day state
4. Arizona – Most of present-day state (southern portion added later via Gadsden Purchase)
5. New Mexico – Most of present-day state (southern portion added later via Gadsden Purchase)
6. Colorado – Western portion (west of Rocky Mountains)
7. Wyoming – Southwestern corner

Key Details

• Total area: ~525,000 sq mi (1.36 million km²)
• Purchase price: $15 million + $3.25 million in assumed U.S. citizen claims against Mexico
• Date: Treaty signed February 2, 1848; ratified May 1848
• Impact: Completed continental U.S. expansion to Pacific; triggered California Gold Rush (1848)

Subsequent Adjustment

The Gadsden Purchase (1854) added ~30,000 sq mi in southern Arizona and New Mexico for $10 million, finalizing the current U.S.–Mexico border.