Two years elapsed before Congress took up the subject again. In the meantime a movement began, under the leadership of George Washington, to promote trade relations between Virginia and Maryland, and to establish trade with the western frontier by the construction of a canal along the banks of the Potomac. Washington became president of the Potomac Company at the time of its organization in 1785, and was its guiding spirit for a period of four years, until 1789, when he resigned from that office to take up his duties as first President of the United States. A trade convention, held at Annapolis, led to the call for the Constitutional Convention, February 21, 1787, to meet in Philadelphia in May of that year. On May 29,1787, the draft of the Constitution submitted by Charles Pinckney, of South Carolina, first mentions the section relating to the Federal district in the form in which it became a part of the Constitution of the United States (Art. I, sec. 8, par. 17), under the powers of Congress-- To exercise exclusive legislation in all cases whatsoever over such district (not exceeding 10 miles square) as may, by cession of particular States, and the acceptance of Congress, become the seat of the Government of the United States, and to exercise like authority over all places purchased by the consent of the legislature of the State in which the same shall be, for the erection of forts, magazines, arsenals, dockyards, and other needful buildings. There was objection on the part of some lest such a provision in the Federal Constitution would create a government that would become despotic and tyrannical and result in unjust discrimination in matters of trade and commerce between the merchants within and outside of the district. But on the other hand the advocates for a Federal City over which Congress would have exclusive jurisdiction called attention to the great importance for the Government to have a permanent residence for the Congress and the executive departments, with their files and records properly housed, and cited the mutiny in Philadelphia as an illustration as to what might happen to the Government again in the absence of such Federal authority. On September 17, 1787, the Constitution of the United States was adopted and soon after was ratified by a majority of the States.