This branch line left the Pennsylvania Railroad mainline in the Baltimore area, and headed west a few miles to Catonsville. The line provided coal to the power plant of the Spring Grove State Mental Health Hospital, at the end of the branch. It also served St. Charles College, and other businesses in Catonsville. Passenger service was also offered along the line.
After the line was first built, the Catonsville Short Line Railroad leased the line to the Baltimore and Potomac Railroad for a short time.
Reports on when it was abandoned conflict. One says it was abandoned prior to the PRR/NYC merger of Penn Central in 1968, another says it was in operation until at least 1973.
Today, little of the former right-of-way is evident. A few blocks east of the branch's endpoint, a segment of track has been paved over in a grade crossing. Another segment is still in place in a thicket of trees nearby, and is being used by a small stream, or possibly water runoff from irrigation. I-695 crosses under what would have been the former right-of-way, but there is no visible evidence of the bridge remaining. It is possible that the widening of the Interstate over the years might have obliterated any abutments or other remnants of the bridge. The area near where the branch ended is now a home for children, but it is marked as private property and there are no obvious track remnants near the street.