I think it is Bombus griseocollis but t may perhaps be Bombus impatiens or Bombus bimaculatus.
These three Bumble Bees are the most common species in the eastern part of the US.

1st & 2nd photo: Gilsland Farm Audubon Center, Falmouth, Maine, USA, 7 August 2017
3rd, 4th & 5th photo: Falmouth, Maine, USA, 6 August 2017