Wyandotte Constitution, in the period immediately preceding the American Civil War, document under which Kansas was admitted to the Union as a free state (Jan. 29, 1861), concluding the struggle known as Bleeding Kansas. Drawn up at Wyandotte (now part of Kansas City) in July 1859, it rejected slavery and suffrage for women and blacks but affirmed property rights for women. The document was approved in a referendum by a vote of about 10,000 to 5,000 (Oct. 4, 1859). Amended many times (including a universal suffrage amendment in 1912), it is still the constitution of Kansas.