Suggest call Amtrak and ask specifically if they will prepare a Kosher for Passover meal for your trip on the Acela. Since Kosher meals are prepared under Rabbinical supervision, I think it's very likely they can accomodate your request (but probably a good idea to bring some snacks just in case they goof like your trip the prior year).

"Availability and Notice
Special menu selections, including kosher, vegan and vegetarian are available on most trains with 72-hour advanced notice. 24-hour advanced notice is required for Acela Express First Class service.

To reserve your meal, call 1-800-USA-RAIL (1-800-872-7245). TTY service is available at 1-800-523-6590.

Kosher Meals
Kosher meals are prepared and wrapped under rabbinical supervision and sealed until delivered to the passenger."