At the Battle of Island Mound, the 1st Kansas Colored Volunteers becomes the first known African American regiment to fight in a skirmish on behalf of the Union. This regiment and the 5th Kansas Cavalry advance on a known guerrilla army in Bates County, Missouri. The Kansans fortify at a homestead (which they name "Fort Africa") on October 27 and keep the guerrilla attackers at bay with their superior weapons. Running low on supplies by October 28, the Kansans advance so that foragers can gather food, and on October 29, the two sides engage in hand-to-hand fighting before the guerrillas flee the field. The Union forces suffer 19 casualties and the guerrillas lose an unknown number. After the Emancipation Proclamation, the 1st Kansas Colored Volunteers are mustered into the U.S. Army on January 13, 1863.