Following the Battle of Fort Sumter, on April 16, 1861, President Abraham Lincoln issued a proclamation to call for 75,000 volunteers to put down the rebellion. Pursuant to that proclamation, the War Department requested each state provide a certain number of regiments of volunteers—they requested one regiment from the state of Wisconsin. However, following Wisconsin Governor Alexander Randall's call to arms, 36 companies of men were enrolled to volunteer for the war effort—enough for more than three regiments. The Second Wisconsin Infantry Regiment was the second unit created from these original volunteer companies. The regiment was organized at Camp Randall, in Madison, Wisconsin, primarily composed of companies from Madison, Racine, Milwaukee, Oshkosh, and La Crosse.