In September, 1857, he sailed for Brazil in company with several other civil engineers and artisans to assist in the construction of the Dom Pedro Segundo Railroad, which ran westward from Rio de Janeiro.
[1] Several months after outbreak of the Civil War, Muhlenberg returned to the United States and enlisted in the Union Army in Philadelphia.
Muhlenberg retained command at the Battle of Antietam, where he served in the artillery of XII Corps under Capt.
After the death of Lt. Franklin B. Crosby, who was senior to him, Muhlenberg resumed command of the battery while serving with XII Corps.
When Captain Best became inspector general of the corps on the staff of Maj. Gen. Henry W. Slocum, Muhlenberg assumed command of the artillery brigade.
Slocum did, however, assign Claremont Best to oversee deployment of the corps’ guns on the morning of July 3, 1863, when a counter attack was made on Confederate forces occupying part of the hill.
[2] When he died of Brights Disease in Lancaster, Pennsylvania, in March 1883, Muhlenberg was described by a newspaper report as a retired major of artillery.