Allan Pinkerton, Abraham Lincoln, and John A. McClernand

Abraham Lincoln standing with two men in front of a tent

Courtesy Library of Congress, LC-DIG-cwpb-04339.

From left to right, Allan Pinkerton (1819–1884), the head of the Union Intelligence Services, President Abraham Lincoln, and Major General John A. McClernand (1812–1900), pose for Alexander Gardner on October 3, 1862, in Sharpsburg, Maryland, just weeks after the Battle of Antietam, the bloodiest single day in American history with some 23,000 combined casualties. The three men well represent the fragile political coalition that allowed Lincoln to mobilize the nation’s resources necessary to defeat the Confederacy. McClernand was a Kentucky native who moved to southern Illinois as a youth, supported Stephen Douglas in the slavery debates of the 1850s, and detested abolitionists. Though a strong Unionist once the war came, McClernand’s influence with Illinois Democrats made him a valuable ally for Lincoln and helped him secure a military appointment. Pinkerton was a Scottish-born skilled worker who was active in the British Chartist movement before coming to the United States. He settled on the northern Illinois plains and became active in the Underground Railroad. With Lincoln’s election, Pinkerton was glad to lend his detective skills to the new president, who escaped an assassination plot in Baltimore on his way to his inauguration thanks to Pinkerton’s work. After the Civil War, as Republican reform impulses waned, Pinkerton became infamous among workers for his strikebreaking activities.