Vice President Joe Biden said the lessons of the civil rights struggle show that the struggle for freedom that began in Philadelphia more than two centuries ago is not over.

Biden took part in the annual "Celebration of Freedom" ceremony at Independence Hall, where speakers recognized the 50th anniversary of the Civil Rights Act and the 60th anniversary of the Supreme Court decision ending school segregation.

Biden said the principles behind the Declaration of Independence led to other landmark legislation involving age discrimination, people with disabilities, and women. He also referred to gay marriage, calling it "the civil rights issue of our day."

And he said what he called "narrow-minded and reactionary forces of the past and the present will never prevail" because of Americans' "basic core decency and honor."