Families marched hand in hand or pushed toddlers in strollers along International Boulevard. Children and adults wore hand-lettered shirts reading "I'm not a criminal" or hefted signs saying "We made this" and "We are the legs U stand on."
Police estimated at least 10,000 people participated in the peaceful march, which started at Saint Louis Bertrand Church near 100th Avenue and ended at a rally at Frank Ogawa Plaza in downtown Oakland.
The Oakland march was one of dozens held Monday throughout the nation to protest federal legislation that would make it a felony to enter the United States without legal documentation and also penalize anyone helping undocumented immigrants.
The issue is one that hit close to home for many who participated in the march.
San Francisco State University student Adriana Perez, 19, says she wonders what the proposed law would mean for her relatives some of whom are here illegally.
"I was born here, but the ones who weren't, they're suddenly criminals?" Perez asked. She wondered about her own fate, too. Would she be targeted for supporting her family members?
Diana, 13, an eighth-grader at Calvin Simmons MiddleSchool in Oakland, spent her first day of spring vacation marching past Lake Merritt with her brother, sister and mother.
Diana is a legal resident of the United States, but her mother, who came to the United States from Mexico when she was a teenager, is not.
"I wouldn't want all my family to be sent away," Diana said. "That's why I'm protesting with my mom."
Teresita Cruz made her way to the City Hall steps to hear speakers chanting and praying in Spanish.
She moved to the U.S. mainland from Guam in 1957, and although the island is a U.S. territory, she still considers herself an immigrant. She said real immigration reform will not divide families.
"HR 4437 is not reform, it's a joke," she said. "We are here to kill that bill. It is not an answer to nothing."
Isaac Menashe of Berkeley joined the rally after watching marchers file by his office building in downtown Oakland.
"I'm here to support the East Bay community who are worried about the draconian legislation proposed in Congress, which would ostracize our neighbors and co-workers rather than give them the welcome and thank you they deserve," said Menashe, an office manager for a public interest law firm.
Several marchers said they hope the national rallies shine a spotlight on the proposed legislation and help force a change in Washington, D.C.
"We're definitely here causing a stir," said Alex Garcia, 17, a junior at Piedmont High School.