The Mexican government and the Americans in Texas were divided due to the issue pertained to the settlement of Texas. Besides that, Santa Anna wanted strong centralized government and didn't want Texas to be independent from Mexico. Some texans wanted to be permitted to have slaves. Mexico refused to recognize Texas Republic, but didn't conquer it.
Those issues were resolved in following steps:
- Anna went in battle at Alamo, killing Crockett;
- they beated Santa Anna and won independence, but buren didn't want to deal with issue of slavery.