The Roger Williams was a six-car streamlined lightweight DMU passenger train built by the Budd Company in 1956 for the New York, New Haven and Hartford Railroad.

For operation into Grand Central Terminal, the cars were each equipped with third-rail shoes, and small traction motors, allowing them to operate into the terminal under electric power, with their engines shut down.

Under Patrick McGinnis, the New Haven ordered three experimental high-speed trainsets in 1955: the Dan'l Webster, the John Quincy Adams, and the Roger Williams.

All had interiors and exterior styling designed by architect Marcel Breuer as part of the new visual identity created by Knoll Associates.

They were moved west on August 17, 2023, to be forwarded to their new home at the Berkshire Scenic Railroad.