Lewis Randolph Bryan, Jr., was born in Quintana, Texas, on August 17, 1892, the son of Martha Jane (Shepard) and Lewis Randolph Bryan. After the Galveston hurricane of 1900, his family moved from Velasco to Houston, where he attended public school. Thereafter, he attended Virginia Military Institute and received a law degree from the University of Texas in 1913. He practiced law in Houston until the United States entered World War I, at which time he was commissioned a captain in the army and assigned to the Thirty-sixth Division. While serving in France he gained promotion to major. In the postwar years Bryan was a lieutenant colonel in the Texas National Guard and was made brevet colonel upon retirement in 1939.
In 1919 he returned to Houston and joined the Lumberman's National Bank (renamed Second National Bank in 1923) as assistant cashier. He rose to the presidency of the bank in 1944. He became vice chairman of the board in January 1956 when the bank took the name Bank of the Southwest. Bryan was an Episcopalian and active in the religious and cultural affairs of Houston. As a great-grandson of Emily Austin Bryan Perry, sister of Stephen F. Austin, he acquired and nurtured an interest in Texas history. He was president of the San Jacinto Museum of History Association (see SAN JACINTO MONUMENT AND MUSEUM) and the Philosophical Society of Texas in 1958. He was also a trustee of the Texas Gulf Coast Historical Association, which, beginning in 1961, has offered an annual prize in his honor for historical writing. Bryan was a member of the Sons of the Republic of Texas and was made a Knight of San Jacinto in 1956.
He was married in San Antonio on November 1, 1924, to Katharine McGown, and they had two sons. At the time of his death on January 30, 1959, Bryan was also a director of the Fort Worth and Denver Railway Company and the Federal Reserve Bank of Dallas, Houston Branch.