Ron Natalie wrote:

There hasn't been a BOS-LGA-DCA shuttle in decades.

Sarcasm, perhaps?

I flew the USAir Shuttle from LGA to BOS routinely during 1998-99.

Additionally, I just checked the USAirways schedule and they still offer
what appear to be shuttle flights hourly from/to BOS, DCA, and LGA. The
USAirways shuttle is an Airbus 319, has been since the late 90s.

--
Peter