Seven agencies working in cooperation with the city sponsored the event.
Volunteers helped people with the naturalization process, which is often the biggest hurdle.
"I think I was intimidated by the whole process. I got busy with working and with life and I put it aside, but every time it was time to vote, I was like 'man, I really want to get my citizenship so I can vote.' So two presidents passed by and I didn't get to vote and yeah, but I'm here," Hayward resident Andrea Almario said.
Organizers say language is the largest barrier in becoming a citizen.
Applicants must pass a language and civics test to get naturalized.