http://www.njtransit.state.nj.us/acl.htm
This is the train map of NJ Transit from Philly to AC. The Philly station
is at 30th St. Station, which you can easily reach via the SEPTA (subway)
for a buck. The schedule for the 30th St. to Atlantic City terminal (which
is at the AC Expressway about six blocks off the Boardwalk) is available
simply by clicking on your start and endpoints and asking for which day.
Fares are $12 ROUND TRIP, and the trains run about every 70 minutes on
Thursday. It takes about one hour and 40 minutes to make the journey on
the train, plus SEPTA and wait time.