Andrew Lee McCormick was born on March 5, 1857, in Marietta, Ohio, to Andrew W. McCormick and Alice J. Leckliter. His father was a lawyer and postmaster who owned $500 of personal property by 1860. He grew up and attended school in Marietta. In 1863, his father encouraged him to “be a good boy, and learn ever so much” at school. “When you get older,” his father continued, “you will learn to know how important it is to be a good scholar.”
McCormick attended college in Marietta, graduating in 1878. He then enrolled at Pulte Medical College in Cincinnati, Ohio. He graduated with honors in 1883 and began practicing medicine in Cincinnati shortly afterward. He also worked as a professor of anatomy at Pulte Medical College. An early biographer described him as a “valued member of the Cincinnati Homeopathic Lyceum and the Homeopathic Medical Society of Ohio.” McCormick reportedly “adopt[ed] all modern methods which his study and examination have proved to be of real benefit in combating disease.”
He married Helen B. Voorhees on August 28, 1890, and their son Harold was born around 1895. By 1900, they employed at least one white servant. He supported the Republican Party, and he belonged to the Congregational Church. He died in Cincinnati on February 26, 1917.