Burr G. Duval, son of federal judge Thomas H. Duval of Austin and nephew of
John C. and Burr H. Duval, Matthew Brady portrait made in his Washington
studio, courtesy of Mrs. E. S. Emerson, San Antonio
Texas State Historical Association. The Southwestern Historical Quarterly, Volume 65, July 1961 - April, 1962. Austin, Texas. The Portal to Texas History. http://texashistory.unt.edu/ark:/67531/metapth101195/. Accessed February 12, 2016.