Delegates of the Free-State Party meet at Osawatomie and reorganize as the Republican Party.

Kansas voters overwhelmingly approve the proslavery Lecompton Constitution, but only because Free-Staters boycott the referendum.

The Free-State city of Lawrence, Kansas attempts to obtain an official charter from the legally unrecognized Topeka Legislature, and then it drafts its own charter. Acting in accordance with the existing Lecompton legislature, Territorial Governor Robert J. Walker declares the charter legally invalid and the city of Lawrence to be in rebellion.

Charles Robinson, an ardent Free-Stater associated with the New England Emigrant Aid Company, is named Kansas territorial governor by the illegitimate Topeka legislature.

Free-Staters attack Franklin, Kansas, and six proslavery settlers are killed.