Protesters also gathered in Atlanta, Miami, Milwaukee, Philadelphia and Washington, D.C., along with a host of other cities.
In Miami, more than 200 people gathered. "You can't justify murder," read one poster. Another read "Don't worry about more riots. Worry about more Zimmermans."
Carol Reitner, 76, of Miami, said she heard about the vigil through an announcement at her church Sunday morning. "I was really devastated. It's really hard to believe that someone can take the life of someone else and walk out of court free," she said.
In Philadelphia, about 700 protesters marched through downtown to the Liberty Bell, alternating between chanting Trayvon Martin's name and "No justice, no peace!"
"We hope this will begin a movement to end discrimination against young black men," said Johnathan Cooper, one of the protest's organizers. "And also to empower black people and get them involved in the system."
In Atlanta, about 75 protesters chanted and carried signs near Centennial Olympic Park.
"I came out today because a great deal of injustice has been done and I'm very disappointed at our justice system," said Tabatha Holley, 19, of Atlanta.
"I'm just disappointed in America."
Associated Press writers Suzette Laboy in Miami, Terence Chea in San Francisco, Keith Collins in Philadelphia, Pete Yost and Eric Tucker in Washington and Luisa Leme contributed to this report.
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