Husband of Martha King Wallace (1849-1932), of Knoxville. He was a foundry operator and an inventor. Over the years, he was also a coal dealer, part owner of a coffin factory, and co-owner of a company that produced wagons and carriages. The water heater for steam boilers, described here in a Scientific American article, was probably his most notable invention. Although he was a good deal older than she, Robert was a first cousin of the well-known Helen Keller, of Tuscumbia, AL.