In February 1830 one Isaac "Vandoin" (probably Van Dorn) was serving as síndico procurador at the regular meeting of the ayuntamiento of San Felipe de Austin. In June 1832 Van Dorn fought in Aylett C. Buckner's company at the battle of Velasco. He was a member of the committee of safety and correspondence at Matagorda in October 1835 and in December was recommended by Joseph W. E. Wallace to Henry Smith as a lieutenant in the artillery. On May 3, 1837, Van Dorn married Amanda Malvina Reader of Adams County, Mississippi; the couple had ten children and were members of Christ Episcopal Church in Matagorda. In July 1837 Van Dorn was elected the first sheriff of Matagorda County, and in late January 1840 he was appointed a commissioner to examine for fraudulent land title claims in the county. In the 1850 census he reported owning three slaves. He died on May 30, 1860, and is buried in the Matagorda Cemetery.
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