Why the United States Annexed Texas (1845)

The annexation of the Republic of Texas was driven by a convergence of ideological, economic, political, and strategic forces:

1. Manifest Destiny

Widespread belief that the U.S. was destined to span the continent; Texas was the immediate western frontier.

2. Economic Interests

• Cotton & Slavery: Texas's fertile lands promised expansion of the plantation economy; Southern politicians sought a new slave state to balance Senate power.
• Resources: Timber, potential minerals, and Gulf ports (Galveston) for trade.

3. Political Ambitions

• President Tyler (1844–45) and President-elect Polk (1845) championed annexation to secure expansionist votes.
• U.S. settlers in Texas (since 1820s) demanded protection and union.

4. Strategic Considerations

• Geopolitical Buffer: Texas separated the U.S. from a volatile Mexico.
• Trade Routes: Control of the Rio Grande, Red River, and Gulf access.
• Pacific Aspirations: Texas annexation paved the way for the Mexican–American War and the acquisition of California/New Mexico.

The joint resolution of Congress (1845) admitted Texas as the 28th state, triggering the Mexican–American War (1846–48).