Amtrak rebuilt and reopened the former PRSL (PRR) route to Atlantic City in May of 1989. The old PRSL service, operated in it’s final years by Conrail under state contract, ended in 1983. The Amtrak trains originated in Philadelphia, Washington, and New York and made one stop between PHL and ACY at Lindenwold. The single intermediate stop for Amtrak was changed to Cherry Hill when that station opened following protracted negotiations with the Garden State Race Track (which owned the land at the station site). The project was jointly funded with New Jersey.
New Jersey Transit began local service between Lindenwold and ACY in September, 1989 after completion of local stations at Atco, Hammonton, Egg Harbor, and Absecon. The NJT service was soon extended into Philadelphia once misgivings by the Delaware River Port Authority (owners of the PATCO line) could be placated. The DRPA owned the old PRSL track from Lindenwold to just west of Haddonfield and feared loss of ridership to the NJT trains.
Sadly, Amtrak’s service was a colossal bust. Predicting 2 million riders a year, they never even hit 200,000. Several efforts were made to find a market, including extending a Washington train to Richmond, extending a New York train to Springfield, MA. They even tried running directly to Philadelphia International Airport via the SEPTA Airport line and introduced a code share with Midway Airlines, but all for naught. There was simply no Philadelphia market for a $25 train to the outskirts of Atlantic City when bus riders could go from their own neighborhoods to the door of the casino for free or less. The longer length trips were better patronized, but they needed hundreds of riders per day and those numbers were simply not there. The service died a quiet death in 1995.
The last remnant of the Amtrak Atlantic City service is the joint ticketing arrangement with NJT. You can still buy a through Amtrak / NJT ticket to Atlantic City with the NJT train given an Amtrak train number like a Thruway bus. That is, to my knowledge, the only joint ticket arrangement between NJT and Amtrak.