Boundary, slave trade, and extradition (Webster-Ashburton Treaty) : Treaty between the United States of America and Great Britain. Signed at Washington August 9, 1842. Ratification advised by the Senate of the United States August 20, 1842. Ratified by the president of the United States August 22, 1842. Ratified by Great Britain October 5, 1842. Ratifications exchanged at London October 13, 1842. Proclaimed by the President of the United States November 10, 1842. And exchanges of notes.