The Mexican Workers program that the ILWU, Local 13 participated in was designed to both provide training for Mexican longshoremen at United States ports and to help unify the longshoremen's unions both north and south of the U.S.-Mexico border. In this letter, three members of a Mazatlan longshoremen's union wrote to Ruben H. Negrete of ILWU, Local 13. Part of the letter reads "With the present letter, we acknowledge that we had the honor of having Mr. Ruben H. Negrete with us, a retired associate from Longshoremen's Local 13 of the United States, this visit from our colleague H. Negrete was as a courtesy, on his behalf, to come and greet his friends that had worked in various ports in the United States, alongside other longshoremen from sister ports. It has been a great pleasure for us, to be able to count on a visit from a colleague from a U.S. port." 11 in. x 8.5 in.