That they were humans.
Improved answer: they had to become Mexican citizens. APEX ;D
Many of them were pro slavery which was in directly opposite to Mexico's antislavery policy.
American settlers wanted slavery.no oneaustin
who led 300 settlers into texas
American settlers did not want to obey the laws. American settlers wanted slavery.
Mexico needed American settlers to help defend its Texas frontier.
Relations between the Mexican government and American settlers in Texas begin to deteriorate because settlers refused to convert to Catholicism or free their slaves.
austin
Mexicans invited the American settlers into Texas. Texas-Mexico invited Americans to settle in Texas to stop Indian attacks. These settlers were required to be Catholic, become Mexican citizens, and follow Mexican laws.
alamo
Slavery.
In Texas
All the above