Gregory Rodriguez, a Los Angeles-based writer researching a book about how Mexico's past may shape the future of the United States, said Mexico was a racial hodgepodge that evolved for five centuries with many of its tensions left unaddressed.
"Mexico is not even comfortable dealing with its white and brown heritage, let alone its black heritage," Rodriguez said.
Mexico's conflicted feelings about its black heritage, Rodriguez said, can be seen in artistic depictions of one of its national heroes, Jose Maria Morelos, a leader in the Mexican War of Independence. In some paintings and sculptures, Morelos, who was partly of African descent, is shown with dark skin and kinky hair. In others, he is light-skinned and more European looking.
Sociologist Luisa Strickland said Mexican blacks -- most of whose ancestors entered the country centuries ago through the Caribbean port city of Veracruz, becoming slave laborers in sugar cane fields -- were Mexico's "forgotten, invisible people."
Veracruz and Guerrero states remain the centers of Mexico's black and mulatto population, estimated at fewer than 1 million of the nation's 105 million people. Roughly 12 million Mexicans are indigenous.
Black Veracruzanos, Cruz said, take pride in their heritage, particularly in the African slave leader Gaspar Yanga, who organized a revolt in the late 16th and early 17th centuries. That resulted in the establishment of Yanga, the first town of free blacks in the Americas.
Mexico abolished slavery in 1829, more than three decades before the United States. But though racism toward blacks is prohibited by law in Mexico, Cruz said, discrimination remains evident in today's popular culture.
"You just have to watch Mexican TV and see the guys who are appearing on the screen. They are blond with blue eyes. Many Mexicans don't even know we have an important black population," Cruz said.
Postal director Islas insisted that the stamps were meant merely to commemorate a beloved cultural figure.
"In the post office, there are no races, there are no colors, no social positions," he said.
"It is just an excellent service that delivers in the most remote places."