He left Tennessee for Texas because of the deteriorating political system

Davy decided to leave the US Congress when he failed to win the election that would have allowed him to serve a fourth term. His resistance to the administration of President Andrew Jackson was a crucial factor in his defeat.

Crockett reportedly told his former constituents, "You may all go to hell and I will go to Texas," when he withdrew from politics and drifted west in 1835. He departed Tennessee that November and arrived in Texas the following January with a small group of followers. His reasons for enlisting in the Texas Revolution were murky; it's possible that he had an eye on a future political position. Nevertheless, he signed an oath to the Republic and consented to use force against Mexico just a few days after his arrival. The 49-year-old had arrived in San Antonio de Bexar by early February and had accepted a position at the Alamo, a former Franciscan mission. Just a few days later, on March 6, 1836, Santa Anna and his Mexican forces surrounded the Alamo and broke through its outer walls. Crockett and about 200 other defenders perished in the ensuing conflict.