The Jayhawkers!

Shortly before the start of the American Civil War rebel Kansas leader Luke Darcy dreams of a new independent Republic of Kansas. His vigilante group is called The Jayhawkers and their mission is to end slavery by force. However, Darcy uses The Jayhawkers for his own bid for absolute control of Kansas. Darcy's actions do not sit well with the military governor of Kansas, William Clayton, who wants Darcy captured and brought to justice. For this purpose the governor hires an ex-renegade rebel, Cam Bleeker, to join Darcy's group and capture their leader. Bleeker has a personal reason for wanting to see Darcy hanged. Darcy was responsible for Bleeker wife's death while Bleeker was in prison. - IMDb