Maryland borders Washington DC, so this question depends on where you are in Maryland. It could be several miles or no distance at all.
Baltimore, Maryland is 25 miles north east of Washington, DC. Some other cities close to Washington, DC are Bethesda, Maryland, and Annapolis, Maryland.
About 150 Miles
It is about 40 miles from DC to Damascus so it takes about an hour.
They share a common border.
Annapolis, Maryland is only 32.6 miles from Washington, DC.
It is 76 miles according to Google Maps.
It is 67.37 miles according to MapQuest.
It is 160.44 miles according to MapQuest.
It is 47.76 miles according to MapQuest.
It is 21.28 miles according to MapQuest.
It is 20.54 miles according to MapQuest.
It is 118.88 miles according to MapQuest.