The following are some of the topics you should focus on during your research about the conflict between the U.S. and Mexico over Texas:
1. The importance to Mexico of holding onto the land it had inherited from Spain after its war for independence.
2. The United States' hope to expand across the North American continent.
3. Mexico's decision to open Texas to foreign settlers.
4. The changing face of the population of Texas.
5. Mexico's decision to centralize its government, thereby restricting the autonomy of its territories like Texas.
6. The Texans' rebellion led by Sam Houston and Texas' subsequent claim of independence from Mexico.
7. The Battle of San Jacinto.
8. Mexico's concern that if it loses Texas to the U.S., it will also lose New Mexico and California.
9. The U.S.'s annexation of Texas and Mexico's subsequent decision to recall its Ambassador to the U.S.
10. The two countries' land dispute regarding the area between the Nueces River and the Rio Grande.