With DL (Connection) dropping its PHL-BOS service this August (see thread-link) http://www.airliners.net/discussions/general_aviation/read.main/1641552/;
I'm curious to know how many carriers have flown the route over the years.
Here's the ones I know right off the bat:
American Eagle (not sure if AA ever flew mainline on this route)
Business Express (under DL and later AA)
Midway (the original, my first PHL-BOS r/t itinerary)
[Edited 2004-07-09 15:52:56]