By the 6th section of the act of 1790, c. 28, Congress provided that it would remove to this District, and make this the seat of government, on the first Monday of December, 1800. It did so; and now its express duty under the constitution, and its implied promise to the state of Maryland, were to be fulfilled, by exercising “exclusive legislation” over this District. In fulfilment of this duty and promise, Congress, on the 27th of February, 1801, by the act of 1801, c. 15, proceeded to legislate for the District of Columbia; and, in the first section of that act, it provided as follows:-- “_Be it enacted, &c._, That the laws of the state of Virginia, as they now exist, shall be and continue in force in that part of the District of Columbia which was ceded by the said state to the United States, and by them accepted for the permanent seat of government; and that the laws of the state of Maryland, as they now exist, shall be and continue in force in that part of the said District which was ceded by that state to the United States, and by them accepted, as aforesaid.” By this act, then, Congress assumed to exercise, and did exercise, that exclusive legislation over the District of Columbia which had been provided for by the constitution. That portion of the District which was ceded to Congress by Virginia, having been receded to that state by the act of Congress of July 9, 1846, (stat. 1846, c. 35,) all that relates to it may, for the purposes of this argument, be laid out of the question. On the 27th day of February, 1801, then, the laws of Maryland, _as such_, were abrogated in this District. The legislative power of Congress was _de facto_ exclusive. All legislative power previously possessed by Maryland over it, then ceased. The connection of Maryland with this District, as a part of its former territory, and occupied by its former citizens, was dissolved. It had no longer any more legislative power over the District than Maine or Georgia had. Historically, we may talk about the laws of Maryland, as they once existed here; but practically, and as a matter of strict law and fact, her laws were no longer known within the District. The laws which governed the people of this District after the 27th day of February, 1801, were the laws of Congress, and not the laws of Maryland. To show that this part of the District passed out from under the government of Maryland, and came under the government of the United States, I refer to _Reilly, appellant_, vs. _Lamar et al._, 2 Cranch, 344; 1 Cond. Rep. 322, where it is said, “By the separation of the District of Columbia from the State of Maryland, the residents in that part of Maryland which became a part of the District, ceased to be citizens of the state.” It was held, in that case, that a citizen of the District of Columbia could not be discharged by the insolvent law of Maryland.