Railroads and terrain

Historical rail lines and terrain around Baltimore, Washington, and the Potomac River.
A work in progress.
Sources
Railroad data
USGS National Transportation Dataset, OpenStreetMap (CC BY-SA 2.0), and U.S. Railroads, 1826–1911, by Jeremy Atack. The OSM data includes extracts from older versions of the database.
Other data sources
NASADEM 30m, USGS National Boundary Dataset, and USGS National Hydrography Dataset — NHD and NHD Plus HR.