It was one of a series of cases dealing with the applicability of previous laws in the newly created District of Columbia.
Prior to the creation of the District of Columbia in 1801, Virginia created a private right of action to enforce most of its criminal statutes.
The law provided that the penalty would be a fine of 150 pounds payable to any party that would file suit against the operator.
[1] This led to a contradiction because the Virginia law, which was supposedly still in force, had no such requirement.
The Court held that it was the object of Congress not to change in any respect the existing laws further than the new situation of the District rendered indispensably necessary.