Civil War Union Brevet Brigadier General. A native of County Donegal, Ireland, his family emigrated to America in 1833 and settled in Cincinnati, Ohio. He graduated from St. Xavier College and worked in the law office of his uncle before moving to Toledo, Ohio to study law. He returned to Cincinnati, was admitted to the bar in Ohio, and practiced as an attorney in Hamilton County. When the Civil War began, he was commissioned as a Captain with the 10th Ohio Volunteer Infantry and worked diligently to recruit men to answer the call for volunteers. At the Battle of Carnifex Ferry, his left arm was seriously wounded and was to be amputated. McGroarty refused to leave the battlefield and continued to command his company on horseback. With his wounded arm dangling at his side, he held a saber in his right arm, and grasped the reins of his horse with his teeth. Surgeons attempted to save a portion of his arm which was eventually removed after a third operation in 1864. According to a medical examiner, and from information gathered from McGroarty's tales, he was believed to have been shot 23 times during the war. Due to injuries that occurred in West Virginia, he resigned in October, 1861, only to return to active duty six months later when he was commissioned as a Lieutenant Colonel for the 61st Ohio Volunteer Infantry. He commanded the regiment when it was attached to the Army of Virginia under Major General John Pope and was promoted to Colonel after the Second Battle of Bull Run. The 61st Ohio was engaged in the Battles of Chancellorsville and Gettysburg in 1863 as part of the XI Corps. He led the regiment during several battles of the Atlanta Campaign and participated in the Battle of Bentonville before his regiment was consolidated into the 82nd Ohio Infantry. He received a promotion to Brevet Brigadier General of U.S. Volunteers on May 1, 1865 for "gallant service". After the war, he was appointed by President Andrew Johnson as a collector of Internal Revenue until he was elected as Clerk of Courts in Hamilton County. He died before he was able to take office at the age of 39. He was initially interred at St. Joseph Cemetery in Price Hill, Ohio. His grave was removed to Spring Grove in 1912 to be buried next to his wife.