United Farm Workers Logo

From Just Another Poster? Chicano Graphic Art in California:

In 1962, Cesar Chávez and his cousin Manuel conceived of the U.F.W. logo as a way to ‘get some color into the movement, to give people something they could identify with.’ they chose the Aztec eagle on the Mexican flag as the logo’s main symbol and created a stylized version of it that was easy to reproduce. The U.F.W. logo became a highly recognizable icon in the union’s boycott efforts, legislative, proposition campaigns, and a victorious symbol of its successful contract negotiations.

The symbol and flag were unveiled at the first mass meeting of the newly formed union.

From Aztlannet:

The evolution of Chicano poster art began in 1965 with the production of graphic images to support the organizing and boycotting efforts of the United Farm Workers. The U.F.W. logo — a black stylized eagle with wings shaped like an inverted Aztec pyramid — became a key symbol of the Chicano movement. It appeared prominently on all official U.F.W. graphics, and its inclusion on unrelated posters made by Chicano artists signaled support for the union. Posters also were utilized to promote other Chicano political causes, such as the 1968 Coors beer boycott in protest of the company’s discriminatory hiring practices.