[Letter from Harris Leon Kempner to Hiram L. McDade, Jr., April 20, 1962], letter, April 20, 1962; (https://texashistory.unt.edu/ark:/67531/metapth1436528/m1/1/: accessed July 16, 2024), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu.; .