"There are a lot of people who have not signed up yet, especially in the Latino community," she said. "If we do not sign up, the whole thing is not going to work."
Huerta also urged the audience to go out and see "Cesar Chavez," a film about the life of the late civil rights leader, which stars Michael Pe? and John Malkovich and opens in some theaters across the country today. Rosario Dawson portrays Huerta in the film.
Faculty members, community activists and college and high school students were among those in attendance and gave Huerta several standing ovations as she talked about the need for more education, immigration reform, a higher minimum wage, women's and LGBT rights and urged the crowd to get more involved in grassroots activism.
"We have to do it with an electoral revolution," she said.
Jasmine Morales, a 16-year-old student at Rancho Cotate High School in Rohnert Park, said she came to see a woman whom she had learned about in school.
"She's an incredible person. She lifts people up," Morales said. "She inspires you to want to change the world."
With Chavez, Huerta helped organize California farmworkers and the famous nationwide boycott of table grapes that helped secure some rights and benefits for farm laborers.
The New Mexico native grew up in Stockton. She received the the Presidential Medal of Freedom in 2012 from President Barack Obama and continues to be active through her own foundation.
Before Thursday's lecture, organizers said Huerta dined with former farmworkers who now own vineyards.
"We have laid a foundation," she said. "But we have so much more to do."