A Georgetown "Cathedral"

Historical marker location:

3116 O Street Northwest, Georgetown, District of Columbia

( Marker is at the intersection of O Street Northwest and 31st Street Northwest, on the right when traveling east on O Street Northwest.)

The city was built on a swamp: The area that is now Washington, D.C. was originally a swampy, marshy region along the Potomac River. The construction of the city involved extensive drainage and landfill projects to make the land suitable for building.