In the years that followed, Jones built a thriving plantation at Barrington and a prosperous medical practice. His wife Mary was devoted to him, and his children were healthy and intelligent. His sister Mary moved back to Texas and opened a schoolhouse nearby where the Jones children and others had their lessons.
Some men might have been happy, but Anson Jones was not. Over the years he grew bitter and obsessed. He spent years copying old diaries and letters, accumulating six hundred pages of manuscript that he said would prove the wisdom of his annexation policies. He traveled to New England, scene of his impoverished boyhood, where he spent months researching his genealogy. He took grim satisfaction when he finally proved that he was a descendant of the famous Cromwell family. Most destructively, he conceived an insane hatred of Sam Houston, becoming convinced that Houston was a villain who would destroy Texas.
In 1849, Jones was thrown from a horse. His left arm was crushed and became withered and discolored. For a time, the severe injury seemed to jolt him into the present. He traveled to the east for medical treatment and became interested in business and new technology, especially railroads. He rejoined the Odd Fellows and became involved in his church. But he soon found that the business world was as corrupt as the politics he had renounced. His arm gave him constant pain that even morphine could not blunt, and he retired once more to a brooding existence at Barrington.
In 1857, both of Texas's seats in the United States Senate were vacant. Sam Houston was running for governor rather than seeking another term in the Senate, and Thomas J. Rusk had committed suicide. Jones believed that he would be chosen by the state legislature to fill one of the vacancies. He traveled to Austin to accept the honor in person. He expected to be greeted by callers eager to hear his views on the future course of Texas. Instead, he sat alone at his inn with his papers and his newspaper clippings. When the balloting took place, he received not a single vote.
Jones was shattered. Thereafter, his life rapidly spiraled out of control. Hastily, he decided to sell his plantation and move the whole family to Galveston to start over. He let Barrington go for only a fourth of its value. Leaving the family still at the plantation, he went to Houston and gave his six-hundred page manuscript to his bankers. It would explain everything about the true founding of the Republic of Texas.
Then Anson Jones checked into the Old Capitol hotel, the wooden building that had once served as the capitol of Texas, the place where he had shed his identity as a failed country doctor and become a respected statesman. He stayed for four days, brooding upon the past. He ate dinner with a friend, telling him that, "My public career began in this house, and I have been thinking it might close here." That night, January 9, 1858, Anson Jones returned to his room and shot himself. He was fifty-nine years old.