Pinkney Lugenbeel was born in Libertytown, Maryland, and was appointed as cadet to the United States Military Academy at West Point, New York in 1835.
Lugenbeel took five years to complete his training, graduating 28th in his class of 1840, which included future Union Army generals William T. Sherman and George Thomas and Confederate States Army generals Richard S. Ewell and Bushrod Johnson.
After appointment as brevet second lieutenant in the army's Fifth Infantry Regiment, Lugenbeel served on the frontier.
Lugenbeel County, South Dakota was named for him, as was Pinkney City, Washington (located three miles northeast of Colville).
He was also credited with improving and building up the Fort Walla Walla–Fort Colville Military Road.