How far is the museum from the train station and are their any hotels near by?

Hotel it will be in downtown have a lot of them between 5 to 6 block depending about your budget Trains station union Station is 2 miles from the musuem

Two blocks from Green Line Smithsonian metro stop.

A friend told me about an app to find, reserve, and pay for parking anywhere, nationally - ParkWhiz. Great tool. We drove and parked in the Reagan Building parking lot. It is a block away.

There are hotels in the area. It was a 2 mile walk from ours.

One block

Not sure about the trains. We parked in the Ronald Reagan building. It was not that expensive. It cost me $17.00 for 5 hours. And Its across the street from the museum.