A day after President Barack Obama identified himself with 17-year-old Trayvon Martin who was shot to death in an alleged racial crime, superstar couple Jay Z and Beyonce joined protesters across on Saturday to protest a not-guilty verdict in the case.
A call for nationwide vigils designed to press for federal action in the emotionally charged case drew thousands to one New York rally.
Elsewhere turnouts were more modest, with the crowds drawn overwhelmingly from the black community, including in Miami where the slain 17-year-old's father spoke. (Read more: Jamie Foxx supports Trayvon Martin's mom)
The surprise appearance of hip hop star Jay Z and his wife, pop superstar Beyonce Knowles, attended a Manhattan protest addressed by Trayvon's mother, Sybrina Fulton, and civil rights leader Al Sharpton.
Fulton vowed to ensure her son's death would not be in vain but pleaded for protests to be kept peaceful. Speaker after speaker compared Martin's death to that of city native Emmett Till, whose racially-motivated murder in Mississippi was a pivotal moment in the civil rights movement. (Read more: Father vows to fight until death as US rallies for 'Justice for Trayvon')
In a message posted on her website, Beyonce also recalled 14-year-old Till's brutal killing in 1955. "We must fight for Trayvon the same way the generation before us fought for Emmett Till," she wrote.
The protests came a day after President Barack Obama publicly identified with Martin and the deep frustrations felt among African-Americans over the verdict. "Trayvon Martin could have been me 35 years ago," Obama said. (Read more: Trayvon could have been me: US President Barack Obama)
The president's remarks - his most expansive since a Florida jury's decision one week ago to acquit neighborhood watch volunteer George Zimmerman - were applauded by many at Saturday's vigils.
The 29-year-old Zimmerman, who said he acted in self defense, fatally shot Martin in the chest on the rainy night of February 26, 2012, during an altercation in a gated community in Sanford, Florida.
A jury of six women, all but one white, cleared him of second-degree murder and manslaughter charges.