Pfeiffenberger was born in Dayton, Ohio on November 14, 1834 to German immigrants. His parents, John and Elizabeth (Miller) Pfeiffenberger, were natives of Baden-Baden, in southwestern Germany. After settling in America, his father became a farmer. Pfeiffenberger received his early education in Ohio where he honed his engineering, construction, and architecture. Shortly after the gold discoveries in California, Pfeiffenberger headed West to pursue his chance of prosperity. After returning to the Midwest, he stopped for a short stay in Alton, IL to visit a friend and former parish priest. Finding Alton’s views, buildings, and history fascinating Pfeiffenberger became a permanent resident of Alton in 1857.