Jones was a restless young man, spending time at Harper's Ferry, Philadelphia, and Venezuela, never making much of a success anywhere. In 1832 he gave up medicine and tried his hand as a commission merchant in New Orleans, where he went broke within a year. Jones next drifted to Texas, where he finally found success as a physician in Brazoria. At first, Jones resisted becoming involved in the tensions between Texas and Mexico, but eventually he became a supporter of Texas independence. When the revolution came, Jones served as judge advocate and surgeon in the San Jacinto campaign.
As Texas struggled to form a republic, Jones found himself drawn to politics. He was elected to the Texas Congress, where he served as chairman of the Committee on Foreign Relations. It was in this role that Jones first became involved with the question of the annexation of Texas to the United States.
