Fredericksburg is a census-designated place (CDP) in Bethel Township, Lebanon County, Pennsylvania, United States. The population was 987 at the 2000 census. Fredericksburg was originally called Stumptown after a disreputable settler named Frederick Stump, who founded the town in 1755, and reportedly massacred an encampment of ten inebriated Indians one winter and sent their bodies down the Susquehanna.