Rick Ewig, "Campbell, John Allen," American National Biography Online, February 2000, http://www.anb.org/articles/04/04-01123.html.
Campbell's real importance, however, is his role in the passage of the nation's first woman suffrage law. In 1889 Wyoming's constitutional convention included a suffrage provision in the aspiring state's constitution. When it joined the Union on 10 July 1890, Wyoming became the first state to grant women the right to vote and hold office. Wyoming became known as "the Equality State," a legacy to which Campbell contributed.