Disenchanted with the gender restrictions on educational attainment, she organized her elite, wealthy peers into La Sociedad with Gabriela Mistral.

While in New York, the Warner Bros. movie Under a Texas Moon (1930) was protested as anti-Mexican by a group of Latinos led by Gonzalo González.

She left her husband, who had become physically abusive, and settled with her daughter in Florida, where she unionized African-American and Latina cigar-rollers with the Congress of Industrial Organizations (CIO).

She became a representative of the United Cannery, Agricultural, Packing, and Allied Workers of America (UCAPAWA), becoming the editor of its Spanish-language newspaper in 1940.

She took a year off from UCAPAWA to travel throughout the U.S., visiting Latino workers on the East Coast, in the Southwest, and allying refugees of the Spanish Civil War to her cause.

Moreno criticized the discrimination, pointing out that "California has become prosperous with the toil and sweat of Mexican immigration attending to its number one industry, agriculture.

Along with longtime friend Bert Corona and attorney Carey McWilliams, she organized the Sleepy Lagoon Defense Committee to exonerate the indicted youths.

She also investigated abuses on the part of servicemen in San Diego, advising city councilperson Charles C. Dail on the matter.

The investigation outraged California State Senator Jack B. Tenney, who lashed out at Moreno, publicly accusing her of engaging in an "anti-American conspiracy."

In 1947, she married Gray Bemis, a navy veteran from Nebraska who had been a delegate to the 1932 Socialist Party of America national convention.

"[5] On November 30, 1950, Moreno and her second husband, Gray Bemis of Nebraska, left the United States via Ciudad Juárez, slowly making their way to Mexico City.

[7] Eventually, the couple settled in Guatemala, but were forced to flee when a 1954 CIA-sponsored coup ousted progressive President Jacobo Arbenz Guzmán.

After the triumph of the 1959 Cuban Revolution and the installation of a Communist government under Fidel Castro, Moreno spent time teaching on the island.

Among them are the muralist and professor Judy Baca, who memorialized the organization of Cal San workers in her Great Wall of Los Angeles.