1. Causes

2. The Mexican-American War
1) Texas Revolution a
4 CAUSES
‘Texans’ were Americans who moved to the Mexican territory of Texas. In the 1830s, Texans declared independence from Mexico. Texans went to war, and eventually forced Mexico to sign a treaty recognizing the new Republic of Texas. This left many Mexican leaders bitter about losing so much land.

3. The Mexican-American War
2) U.S. Annexation of Texas a
4 CAUSES
After gaining independence from Mexico, Texas was its own country for about ten years ( ). But they were not strong enough to protect their own borders from invaders or threats, so they considered joining the United States. Texas was formally ‘annexed’ by the United States in 1845, making it the 28th state of the union. This only made relations mores strained with Mexico.

4. The Mexican-American War
3) Border Dispute a
4 CAUSES
For years, the results of the Texas Revolution did not resonate well with Mexicans. Around the time of the U.S. annexation of Texas, border disputes arose between the United States and Mexico. The United States claimed the border to be the Rio Grande while Mexico believed the border was at the Nueces River.
Nueces River
Rio Grande

5. The Mexican-American War
4) Americans in Alta California a
4 CAUSES
Meanwhile in the Mexican territory of Alta California, there were Mexicans called Californios (Mexicans in California) and Anglos (Americans in California). Even though there were fewer Anglos, they were becoming increasingly influential in the region.