Editing Mark Hanna (section)

==Civil War service==
By the start of the [[American Civil War|Civil War]], he was a major participant in the business.  Dr. Hanna had fallen ill with complications from his spinal injury (he died on December 15, 1862), and Mark Hanna, even before his father's death, was made a partner.{{sfn|Croly|p=43}}

With an ill father and many business responsibilities, Mark Hanna could not be spared by his family to join the Union Army, hiring a substitute to enlist in his place.  Instead, he became a member of the Perry Light Infantry, a regiment of [[National Guard of the United States|National Guard]] troops consisting mostly of young Cleveland businessmen.  In 1864, his regiment was briefly mustered into active service as the [[150th Ohio Infantry]] and sent to be garrison troops at [[Fort Stevens (Washington, D.C.)|Fort Stevens]], part of Washington, D.C.'s defenses.  During the time the Perry Light Infantry was in service, it saw brief combat action as Confederate General [[Jubal Early]] feigned an attack on Washington.  However, Hanna, who had been commissioned a [[second lieutenant]], was absent during that time, having been sent to escort the body of a deceased soldier back to Ohio.  The regiment was mustered out in August 1864.{{sfn|Croly|pp=44–46}}  After the war, Hanna was elected a companion of the Ohio Commandery of the [[Military Order of the Loyal Legion of the United States]]—a military society of officers of the Union armed forces and their descendants.