Ruane graduated from the University of Minnesota in 1945 with a degree in electrical engineering and from Harvard Business School in 1949.
He enlisted in the U.S. Navy and was on his way to Japan when World War II ended.
In 1992 he adopted a block in the Harlem neighborhood of New York City, committed to make it a better place, renovating buildings and establishing clinics and community service programs.
Ruane gave every child on the block a scholarship to a Catholic school.
He had four offspring: his sons were William Jr., who lived in Cambridge, Massachusetts, and Thomas, of Washington, Connecticut.