"Fifty-eight years and nothing's changed," Miller said, pausing to join a chant for "Justice for Trayvon, not one more."
In New York City, hundreds of protesters marched into Times Square on Sunday night, zigzagging through Manhattan's streets to avoid police lines. Sign-carrying marchers thronged the busy intersection, chanting "Justice for! Trayvon Martin!" as they made their way from Union Square, blocking traffic for more than an hour before moving on.
In San Francisco and Los Angeles — where an earlier protest was dispersed with beanbag rounds — police closed streets as protesters marched Sunday to condemn Zimmerman's acquittal.
Los Angeles Mayor Eric Garcetti urged protesters to "practice peace" after the rock- and bottle-throwing incident. Police arrested one man.
Rand Powdrill, 41, of San Leandro, Calif., said he came to the San Francisco march with about 400 others to "protest the execution of an innocent black teenager."
"If our voices can't be heard, then this is just going to keep going on," he said.
Earlier, at Manhattan's Middle Collegiate Church, many congregants wore hooded sweatshirts — similar to the one Martin was wearing the night he was shot — in a show of solidarity. Hoodie-clad Jessica Nacinovich said she could only feel disappointment and sadness over the verdict.
"I'm sure jurors did what they felt was right in accordance with the law but maybe the law is wrong, maybe society is wrong; there's a lot that needs fixing," she said.
At a youth service in Sanford, Fla., where the trial was held, teens wearing shirts displaying Martin's picture wiped away tears during a sermon at the St. Paul Missionary Baptist Church.
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 for a vigil. "You can't justify murder," read one poster. Another read "Don't worry about more riots. Worry about more Zimmermans."