Jonas Harrison, lawyer and public official, the son of William and Elizabeth Harrison, was born in Woodbridge Township, New Jersey, on October 11, 1777. In 1807 he was in Michigan Territory, where he was admitted to the bar. By 1809 he was in Lewiston, New York, and was collector of customs for the United States and master of chancery for the state of New York for the same territory. In Lewiston Harrison married Betsy Cooke in 1811. In December 1813 he and other residents of Lewiston were driven out by the British and their Indian allies. After the conflict the Harrisons moved to the rebuilt village of Buffalo Creek (now Buffalo, New York), which had also been destroyed by the British. Harrison became an influential member of the bar, a founder of Saint Paul's Episcopal Church, a director of the Bank of Niagara, and a trustee of the town. He also took a leading role in the effort to have the Erie Canal enter Lake Erie at Buffalo. The home he built for his family was said to have been the finest house in Buffalo. Harrison was ruined by the panic of 1819, and even the sale of his property was not sufficient to pay his debts. Facing the possibility of imprisonment for debt, he left his wife and his three children in Buffalo on a prospecting trip. They never heard from him again.
In 1820 he married Ellender Shannon in Georgia, and they moved to Texas in December 1820. Legends of Harrison's early days in the area indicate that he dressed and spoke as an uneducated frontiersman, taking no part in political or legal affairs. By 1827, however, he was practicing law on at least a part-time basis and serving as acting commissary of police of Tenehaw Municipality. From 1828 through 1831 he was alcalde of the municipality. He was a delegate to the Convention of 1832 from Tenehaw. He had supported the Mexican government but took an active role in several of the meetings in East Texas in 1835, and his conversion to the cause of Texas independence is said to have been enormously influential. Although his health was failing in 1835, he took the title of "major" and was active in recruiting for the armies of Texas. His last public appearance occurred on July 4, 1836, when he addressed a San Augustine meeting called to honor Sam Houston on his return from New Orleans. Harrison died on August 6, 1836. Harrison County was named in his honor.