"In the winter of 1861 Abraham Lincoln left his home in Springfield, Illinois to become President of the United States. Southern states reacted to the election of a Republican president by seceding from the Union, and the nation descended into Civil War. Although the combatants fought no battles on Illinois soil, the Civil War defined an era in the state. Illinoisans shaped the war's course and felt its effects. This website presents primary source material from the Civil War era in Illinois.