William married Nettie May Jackey on 25 Dec 1912 in Butte-Silver Bow County, Montana, USA. Nettie (daughter of Peter Jacky Jackey and Elisabetha Zehnder) was born on 25 Nov 1889 in Shullsburg, Lafayette County, Wisconsin, USA; died on 23 Jun 1970 in Spokane, Spokane County, Washington, USA. [Group Sheet] [Family Chart]

1. Dr. Roger William Clapp was born on 30 Aug 1914 in Butte-Silver Bow County, Montana, USA; died on 18 Feb 1974 in Virginia, USA.
2. Amy Elizabeth Clapp was born on 26 Jun 1916 in Butte-Silver Bow County, Montana, USA; died on 27 Sep 2000 in Spokane, Spokane County, Washington, USA.
3. Alice Jeanette Clapp was born on 18 Sep 1918 in Butte-Silver Bow County, Montana, USA; died on 18 Sep 1937 in Butte-Silver Bow County, Montana, USA.