Dr. Frederick Strayer Diefendorf, M.D., was the son of Delevan and Margaret (Strayer) Diefendorf. They were a farm family living in Canajoharie, Montgomery Co., NY. In 1894 Frederick married Ada Bertha Garlock. The couple was divorced sometime between 1910 and 1914, and Frederick married Anna Frederica Hafner about 1915. They had one child, Helen Hafner Diefendorf, born in 1916.