Final answer:
Mexico saw opening Texas to Americans as a mistake due to the Americans' unwillingness to follow Mexican laws and integrate culturally, as well as their continued practice of slavery despite Mexican laws to the contrary. These tensions led to the Texas Revolution and long-term issues with racial antagonism and land dispossession.
Step-by-step explanation:
Mexico began to see that opening Texas to Americans was a mistake for several reasons. Initially, the Mexican government encouraged American settlers, hoping they would integrate into the Mexican community and protect the territory from Native American attacks. However, the American settlers in Texas showed a reluctance to abide by Mexican laws, including the official language and settlement regulations. Additionally, the American immigrants held onto their own cultural and religious identities, choosing not to assimilate.
The situation was exacerbated by the Texan settlers’ disregard for Mexican slavery laws. Slavery was a contentious issue, as it was largely outlawed in Mexico, but many Texan settlers from southern states brought enslaved people with them and resisted Mexican authority on the matter. As a consequence, the Mexican government outlawed further U.S. immigration in 1830 and increased its military presence, efforts that ultimately failed to stem the tide of illegal U.S. immigration.
The culmination of these tensions led to the Texas Revolution, which saw Texas break away from Mexican control. This action set the stage for subsequent annexation by the United States and a pattern of racial antagonism and dispossession of lands from Mexicans and Mexican-Americans that would last for decades, creating long-lasting problems.