The railline from Washington over Baltimore towards New York has a stop at Baltimore Washington international airport.
Railways in the USA: amtrak.com
A subway system, which upon completion will be about 160 km (about 100 mi) long, was opened in the mid-1970s and extends into the Maryland and Virginia suburbs. Subway service combined with bus service provides an effective transportation network.
from Washington by train to :
in 1 hour
in 2 hour
in 3 hour
in 7 hours
by 2747.com / world / station / Washington DC