DR. IRWIN T. O'BRYAN

Dr. Irwin T. O'Bryan graduated from the Tulane Medical School.He came to Texas in 1846 and was appointed as a Lieutenant in the Sixth Texas Cavalry.He remained in Texas after the war and practiced for 35 years in Waco, McLennan Co., Texas.
This information comes from a biography of his son, Julian Blaine O'Bryan.Did this unit exist and does he appear on the roster?

Thanks,
Jim Cowan