Washington, D.C. is 48% larger than Fargo, North Dakota.
Area: 120 km2 calculated
Fargo is the largest city in the State of North Dakota, accounting for nearly 16% of the state population. Fargo is also the county seat of Cass County. According to the 2013 United States Census estimates, its population was 113,658. Wikipedia
Area: 178 km2 calculated
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. Wikipedia