Many of the "Afro-Mestizos" are descendants of slaves brought to Mexico. The "Costa Chica" of both Guerrero and Oaxaca probably have the largest concentration of Afro-Mestizos. The Municipio of Cuajinicuilapa, Guerrero is reported to be the home to 50,000+ such persons. Acapulco has a very large Afro-Mestizo presence, and many African-Americans visit there in groups ... or did so in larger numbers before the Mexican terrorism problem.
However, you won't likely find much connection in lifestyles or sympathy between the Afro-Mestizo's and African-Americans. Very different cultures. Peoples in the Afro-Mestizo communities of Guerrero, Oaxaca and Veracruz are suspicious of all outsiders ... including African-Americans.
Afro-Mestizos, and blacks generally, in Mexico tend to be at the bottom of the economic scale ... and discrimination against indigenous and poor, and blacks in Mexico is rampant in much of the country from what I've witnessed. Blacks may be welcomed open-armed in White expat, progressive political communities, and amongst Canadian expats ... but don't confuse the politically liberal expat community with the broader Mexican community.
There have been several prominent, successful Afro-Mestizo political leaders and businesspersons, nationally ... however.
LW