The Rev. Al Sharpton, president of The National Action Network, organized the march with Martin Luther King III to "promote a modern civil rights agenda that includes one standard of justice and decency for all people," the NAN Web site said.
"The Justice Department wouldn't come to the people," Sharpton said before the "March on Hate Crimes" began, so "we brought the people to the Justice Department."
Once completing the five-block walk, demonstrators walked round the Justice Department building seven times, symbolic of Gideon's march around the walls of Jericho seven times before they fell.
"It's tragic that we still have to march," King told CNN. "I feel very bad that we're not further along. America is not treating its citizens of color ... correctly."
Reports of incidents involving nooses -- hung from the office door of an Ivy League professor, the basement locker room at a police station and from a schoolyard tree in Louisiana -- have risen during the past 18 months, CNN said.