William Butler was the third Butler brother. Born in 1864, William held the position of manager of general contract operations and also treasurer from 1894-1916. William Butler passed away in 1916. He and his brother Walter were founding members of Bricklayers Local 1 in St. Paul, but as an owner of the company employing workers on the Capitol project, he would not have been an active member of the union at that time. William was the on-the-ground manager of the State Capitol construction.

William was interviewed in 1904 for an article in a local newspaper about the capitol construction. http://www.whobuiltourcapitol.org/articles/how-capitol-was-built-st-paul...