August 01, 1861
To the Senate of the United States:
I submit herewith, for consideration with a view to ratification, a postal treaty between the United States of America and the United Mexican States, concluded by their respective plenipotentiaries on the 31st ultimo.
ABRAHAM LINCOLN.
Abraham Lincoln, Special Message Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/201988