Nelson Mandela leaves the capital today assured of some political support and buoyed by a tumultuous rally where he was serenaded, praised and nearly worshipped by more than 19,000 Washingtonians. ``We thank you, America. We thank you for being true to your responsibility ... We thank you for responding to our cause,'' the black South African leader told the cheering crowd Tuesday night. Mandela was leaving today for Atlanta after a three-day Washington visit during which he won assurances from President Bush and members of Congress of continuing U.S. economic sanctions against South Africa's white government. The 71-year-old African National Congress leader also called Tuesday for financial assistance to his country once the apartheid system of racial segregation is abolished.
