Trayvon Martin's murder unleashed a national debate over racial profiling, self-defense and equal justice.
In Washington, the Justice Department said it is looking into the case to determine whether federal prosecutors should file criminal civil rights charges now that Zimmerman has been acquitted in the Florida case.
President Barack Obama called the death of 17-year-old Martin a tragedy for the country and urged calm reflection, a message shared by religious and civil rights leaders hoping to ensure peaceful demonstrations.
In San Francisco and Los Angeles, where an earlier protest was dispersed with beanbag rounds, police closed streets as protesters marched to condemn Zimmerman's acquittal.
Hours after the verdict, demonstrators gathered in Washington chanting, "No justice, no peace." One protester carried a sign that read, "Stop criminalizing black men."
Civil rights leaders, including the Revs. Jesse Jackson and Al Sharpton, urged peace in the wake of the verdict. Jackson said the legal system "failed justice," but violence isn't the answer.
"While the verdict may be legal, a system that doesn't take into account what happened is a broken legal system," said Jennifer Lue, 24, an Asian-American resident of New York. "Everyone should feel about this, whether you're Asian-American or African-American," she said.
