His mother married Colonel Samuel Dent; they moved to Alabama in 1823.

In early March 1836, his company joined James Fannin's command in south Texas.

Horton's scouts located Col. Juan Morales nearing Goliad with the Jiménez and San Luis battalions on March 17.

The next day Horton was busy skirmishing with General José de Urrea's advance forces.

Upon hearing artillery fire, he returned to find that Fannin and his troops had been surrounded and possibly overrun, Horton and his men after assessing the situation turned and retreated towards Victoria, where reinforcements were expected to be located,[4] an action that would shadow his political career.

He attended the Democratic National Convention in Charleston, South Carolina, in 1860 and the state Secession Congress in 1861.

He was an original member of the board of trustees that founded Baylor University.