1.14 - Illegal Immigration
In 1830, Mexican Centralists outlawed future Anglo immigration to Texas and walked back the freedoms recognized by the 1824 Federalist Constitution. San Antonians - who had long been the loudest advocates for both immigration and Federalism - responded with a bold defense of their new neighbors and an even bolder threat to break away if Centralists wouldn't respect their hard-won rights.
Recommended resource: David Marion Wilkinson, Not Between Brothers
