Charles Mays, 60, is charged with child endangerment and numerous drug and traffic violations.
Mays was pulled over at 3:23 p.m. Friday on Route 13 near I-295 in New Castle.
During the stop, police say Mays agreed to a search of the vehicle. During that search, officers from the Delaware River and Bay Authority say they found Percocet and Oxycodone pills hiding the child's backpack, which was still in the car.
Mays was arrested, and the girl was released to the custody of her mother.
Police have not said what Mays' relationship to the child was.
He was sent to prison in lieu of $13,000 cash bail.
