An estimated 3,000 people gathered Saturday at City Hall in Fresno, Calif., to demonstrate for same-sex marriage rights, police said.

Five days after the California Supreme Court upheld the legality of Proposition 8 -- which stripped same-sex couples of the right to marry in the state -- activists campaigned in the state's conservative Central Valley to try to reverse Proposition 8, the Los Angeles Times reported.

The rally in Fresno followed a 14.5 mile march from Selma, Calif. Organizers said the town was chosen as a focal point of the demonstration to draw a parallel with the 1960s civil rights movement, which featured historic marches in Selma, Ala., the newspaper said.

Celebrities including Oscar-winning actress Charlize Theron and Emmy-winning actor Eric McCormack participated in the demonstration. McCormack, a heterosexual actor who gay lawyer Will Truman on the NBC comedy "Will & Grace," said characters such as the one he played on TV helped gays gain more acceptance in America.

"We are the gays they accepted," he said.