CUNY New York City College of Technology to Gettysburg, PA buses and trains from $25

Here are some trips other travelers have found on Routefriend.
$25
3h 45m
0 stops
GotoBus
$37
4h 55m
1 stop
GotoBus Amtrak
$38
5h 30m
1 stop
GotoBus Amtrak
$68
6h 30m
2 stops
GotoBus Amtrak