William Cappelmann was educated at Newberry College, receiving an A.B. degree, the University of South Carolina, receiving an LL.B. and M.A. degrees, and did graduate work at Harvard Law School and the University of North Carolina Law School.
He practiced law in Columbia from 1913 until his death, except during World War I, during which he served as an officer in the United States Army.
His broad interests are evidenced by the organizations that he was active in at different times in his life: the Columbia Chamber of Commerce, the Richland County Bar Association, the South Carolina Bar Association, the South Carolina Board of Law Examiners, the Crippled Children's Association, the American Legion, the United Lutheran Church and the Lutheran Seminary to name only a few.
“Mr. Cappelmann was an able lawyer and lived to serve all that is best in society.”