Gentlemen of the Senate:
I lay before you the following report, which has been made to me by the Secretary of State:
DECEMBER 22, 1791.
The Secretary of State reports to the President of the United States that one of the commissioners of Spain, in the name of both, has lately communicated to him verbally, by order of his Court, that His Catholic Majesty, apprised of our solicitude to have some arrangements made respecting our free navigation of the river Mississippi and the use of a port thereon, is ready to enter into treaty thereon at Madrid.
The Secretary of State is of opinion that this overture should be attended to without delay, and that the proposal of treating at Madrid, though not what might have been desired, should yet be accepted, and a commission plenipotentiary made out for the purpose.
That Mr. Carmichael, the present charge' d'affaires of the United States at Madrid, from the local acquaintance which he must have acquired with persons and circumstances, would be an useful and proper member of the commission, but that it would be useful also to join with him some person more particularly acquainted with the circumstances of the navigation to be treated of.
That the fund appropriated by the act providing the means of intercourse between the United States and foreign nations will insufficiently furnish the ordinary and regular demands on it, and is consequently inadequate to the mission of an additional commissioner express from hence.
That therefore it will be advisable on this account, as well as for the sake of dispatch, to constitute some one of the ministers of the United States in Europe, jointly with Mr. Carmichael, commissioners plenipotentiary for the special purpose of negotiating and concluding with any person or persons duly authorized by His Catholic Majesty a convention or treaty for the free navigation of the river Mississippi by the citizens of the United States under such accommodations with respect to a port and other circumstances as may render the said navigation practicable, useful, and free from dispute, saving to the President and Senate their respective rights as to the ratification of the same, and that the said negotiation be at Madrid, or such other place in Spain as shall be desired by His Catholic Majesty.
In consequence of the communication from the Court of Spain, as stated in the preceding report, I nominate William Carmichael, present charge' d'affaires of the United States at Madrid, and William Short, present charge' d'affaires of the United States at Paris, to be commissioners plenipotentiary for negotiating and concluding with any person or persons who shall be duly authorized by His Catholic Majesty a convention or treaty concerning the navigation of the river Mississippi by the citizens of the United States, saving to the President and Senate their respective rights as to the ratification of the same.
George Washington, Special Message Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/200827