Charles F. McKenna was born in Pittsburgh, PA, on October 1, 1844 to James and Anna McKenna. He and his twin brother were the youngest of six children, born shortly before their father's death in 1846. McKenna attended schools in Pittsburgh until, at age 14, he apprenticed to a lithographer, due to his interest in sketching. He would continue to sketch throughout his life, even providing illustrations for a published history of the 155^th Regiment, Pennsylvania Volunteers he edited.

McKenna attempted to enlist in the 63^rd Regiment, Pennsylvania Volunteers, in August of 1861, but was forced to postpone, owing to his mother's disapproval and her subsequent poor health. In July 1862, at the age of 16, he joined Company E, 155^th Regiment, Pennsylvania Volunteers. Less than a month after enlisting, McKenna's regiment was on the front lines at Antietam. Over the next three years, he would participate in some of the most pivotal battles of the Civil War: Gettysburg, Chancellorsville, Mine Run, Fredericksburg, and Appomattox. During the long winter encampments, he continued his education with Sergeant George P. Fulton who, folllowing the war, would serve as principal of the Highland Public Schools in Pittsburgh. McKenna served nearly three full years, obtaining leave only once, in January 1865. After his discharge in June 1865, he returned home to Pittsburgh.

In 1869, following several years work in a Pittsburgh law firm, Charles McKenna was admitted to the Allegheny County bar. He was an early memeber of the Allegheny County Bar Association, as well as a charter member of the Pennsylvania State Bar Association. On October 1, 1872, he married Miss Virginia White. The couple never had any children.

While serving as a Pennsylvania Supreme Court judge in 1904, he was offered the Judgeship of the United States District Court of Porto Rico [sic]. McKenna initially declined the offer, but soon changed his mind. He established the first Elks lodge in Porto Rico [sic] while living in San Juan. He returned to Pittsburgh in late 1906, unable to adapt to the climate. In addition to practicing law again, this time with his nephews, McKenna began to work extensively with Civil War organizations.

First appointed to the Gettysburg Battlefield Commission, he went to to serve as its president for many years. He wrote articles for the Western Pennsylvania Historical Society on topics in local history and the Civil War. In 1910, he edited and illustrated a detailed history of the 155^th Regiment, titled Under the Maltese Cross, from Antietam to Appomattox, the Loyal Uprising in Western Pennsylvania, 1861-1865; Campaigns 155th Pennsylvania Volunteers Regiment, Narrated by the Rank and File. He also created an index of Pennsylvania soldiers who participated in the Battle of Gettysburg for the Pennsylvania Historical Society. At the Battle of Gettysburg 50^th Reunion in 1913, he and other survivors received commemorative Congressional Medals of Honor for service.

In 1911, then-Pennsylvania Governor John K. Tener appointed McKenna to the newly established County Court of Allegheny County. In 1921, he was elected to complete a second ten-year term. His service was cut short by his death on December 3, 1922.