As a follow-up, I'd like to link to an article which appeared the day after Memorial Day, reporting on the ceremony held there.
U.S. ambassador Tony Garza participated by laying the memorial wreath, and reading the Gettysburg Address.
An American Legion post in Mexico City participated in the ceremony, by trooping, posting and retiring the colors. Post #2 commander John Lambuth gave a speech, remembering the veterans of the post who had passed away the previous year.
It's good to know that there are Americans in Mexico City taking care of our cemetery.