Washington ? The controversial appeal for slavery reparations comes to the nation’s capital Saturday when supporters from around the country will gather on the National Mall for a “Millions for Reparations” march and rally.

The daylong event is sponsored by several black activist groups seeking to raise awareness of efforts to win compensation for families whose African ancestors were enslaved before 1865 when the practice was outlawed in the United States.

“The U.S. government owes black people reparations for 250 years of free labor to help build this country and for years of legal segregation in the United States that still impacts the nation’s institutions,” said Conrad Worrill of Chicago, national chairman of the National Black United Front, one of the groups organizing the rally.

The march, whose theme is “Reparations Now: They Owe Us,” comes amid a continuing national debate on the effects of slavery and the question of whether the government or individual beneficiaries can be held responsible for slavery’s effects more than a century later.

The rally is timed to commemorate the 115th anniversary of the birth of Marcus Garvey, a black nationalist who urged African-Americans in the 1920s to emigrate to Africa. The day’s activities will begin with a march from Robert F. Kennedy Stadium to a site on the National Mall near the Capitol where, at noon, speakers will address the crowd.

Planning for the event began after a United Nations Conference on Racism last year in Durban, South Africa, declared slavery a crime against humanity. Conferees issued a formal statement that governments have a moral obligation to counter the lasting consequences of slavery. The statement notes that some countries have “taken the initiative to apologize (for slavery) and have paid reparation(s) where appropriate.”

Event organizers won’t make predictions about attendance, but supporters from 66 cities in 38 states are sending delegations, according to Worrill. Among the cities, he said, are Detroit, Houston, Kansas City, Mo., St. Louis, Philadelphia, New York, Cleveland and Milwaukee.