1869 Cheyenne was incorporated under Charter by the First Territorial Legislative Assembly on December 10, 1869. It had previously been incorporated under Dakota Territory Law on August 9, 1867. Governor John Campbell of the Wyoming Territory approved the first law in U.S. history explicitly granting women the right to vote.
1935 December 10 was designated by Statute as Wyoming Day and first celebrated officially on December 10, 1935; "In recognition of the action of the Wyoming territorial governor on December 10, 1869, in approving the first law found anywhere in legislative history which extends the right of suffrage to women, December 10 of each year is designated as 'Wyoming Day.' The day shall be observed in the schools, clubs and similar groups by appropriate exercises commemorating the history of the territory and state and the lives of its pioneers, and by fostering in all ways the loyalty and good citizenship of its people."