Charles Philip Muhlenberg was born on November 24, 1837, in Lancaster, Pennsylvania, to Frederick A. Muhlenberg. His father was a physician who owned $21,000 of real estate by 1850. He grew up and attended school in Lancaster before enrolling at Pennsylvania College (present-day Gettysburg College). He graduated in 1856, and he earned a living as a lawyer in Reading, Pennsylvania. He supported the Democratic Party.
He enlisted in the Union army in the spring of 1861, and he mustered in as a private in Company A of the 25th Pennsylvania Infantry. The regiment served on garrison duty near Washington, D.C., and he mustered out on July 23, 1861. He joined the Regular Army soon afterward, and he received a commission as a 1st lieutenant in the 5th United States Artillery. He received a brevet promotion to captain for “gallant and meritorious service” in the Battle of Cold Harbor. He remained in the army after the war, and he resigned in 1867.
He returned to Reading after leaving the army, and he resumed his work as a lawyer. A local writer described him as a “young man of much ability.” He was a “fluent speaker [who] gave promise of attaining considerable prominence in his profession.” He died of pneumonia on January 9, 1872.