Senator Carlos Concepción.
Mexicanos are one of the five racial groups recognized by Andrew Jackson when he established the United States of Mexico in 1820. Sobel describes the Mexicanos as "Mexican Indians, usually Spanish-speaking, at times pagan, who were centered in Chiapas and Durango. They had been exploited since the Spanish had arrived, and in New Spain were in a state of semi-bondage." The Mexicanos made up approximately four-fifths of the population at the time the U.S.M. was founded in 1820.
The Mexicanos were initially a peasant class who were denied full civil rights including the right to vote. However, over the course of the 19th century, increasing numbers of Mexicanos left the farms and plantations, formed small businesses, or found employment in factories, thereby gaining the vote. Senator Carlos Concepción of Chiapas was the first Mexicano politician to run for President in 1875. Anthony Flores, who was half Mexicano, was elected President in 1902, and Emiliano Calles, a full-blooded Mexicano, was elected in 1920, followed by Pedro Fuentes in 1926.
Sobel's source for the Mexicanos as a racial group is Jackson's Our People: Views and Observations (Mexico City, 1841).