James Perry Bryan, Sr., lawyer, historian, and collector, was born on January 11, 1909, in Bay City, Texas, the son of W. Joel and Cassie (Perry) Bryan. He graduated valedictorian of his class at Freeport High at the age of fifteen, graduated from the University of Texas at age twenty, and attended law school at the University of Texas. Admitted to the Texas bar at age twenty-two, he began his legal career with the firm of Masterson and Bryan in Angleton. In 1936 he was elected county attorney of Brazoria County and joined Dow Chemical in 1940. He served Dow as general counsel from 1942 to 1958 and was vice president of Brazos Oil and Gas Company from 1946 to 1958. Bryan also had extensive banking, business, and real estate interests in the Brazoria County area. He was chairman of the board and owner of the Lake Jackson State Bank, founder of Southern Materials, owner of Brazosport Seafood Company, founder of American Savings and Loan Association, and a participant in numerous oil and real estate ventures. His community service included participation on the school boards of Brazoria County and the Angleton Independent School District. During World War II he was a member of the Eighth Regional War Labor Board and was an organizer and first president of the Brazoria County War and Community Chest.
A descendant on the maternal side of Stephen F. Austin, Bryan displayed a lifelong interest in Texas history and made significant contributions as an author and collector to the field. He was a member of the Texas Philosophical Society, served as president of the Texas State Historical Association, and was a member of the Sons of the Republic of Texas and the San Jacinto Museum of History Association. In 1957 he was appointed a regent of the University of Texas where he gave enormous support to Chancellor Harry H. Ransom while the latter built an internationally known library of rare books and materials for the Harry Ransom Humanities Research Center. Bryan was known as a discerning collector of Texana and amassed one of the most important collections of early Texas maps. His definitive assemblage of approximately 159 rare maps of Texas and the Southwest dating from 1513 was acquired by the University of Texas and served as a model for later collectors and historians writing in the field of cartography. His own publications include Texas in Maps (1961), a history of the state as illustrated by approximately twenty-three maps from his and other University of Texas collections; his edited edition of Mary Austin Holley: The Texas Diary, 1835–1838 (1965); and Gordon Reed: A Novel of the Real Texas Oil Industry (1968).
Bryan married Gretchen Smith on August 24, 1938; they had two sons. His second wife was Betty Bingham who survived him. J. P. Bryan, Sr., died in Houston on June 9, 1975, and was buried at Peach Point Plantation.