Argosy University-Washington D.C. to New Haven, CT buses and trains from $43

Here are some trips other travelers have found on Routefriend.
$43
6h 31m
1 stop
GotoBus Metro-North
$43
9h 22m
1 stop
GotoBus Metro-North
$46
6h 43m
1 stop
GotoBus Metro-North
$54
7h 39m
1 stop
GotoBus Amtrak