WASHINGTON — President Barack Obama served plates of steaming hot lunches to the needy today, one of several ways the nation's first black president paid tribute to Martin Luther King Jr. on the federal holiday that honors the slain civil rights leader.

Obama also scheduled a White House talk with black elders and their grandchildren about the movement for racial equality that King led until he was assassinated in 1968. The president also was to speak later today during a musical celebration of King's legacy at the Kennedy Center.

Obama spent the day with King observances.

"How are you sir? God bless you," the president said, greeting one man among the dozens of men and women who filed into the dining room at SOME, or So Others Might Eat.

The organization, just a short ride from the White House, provides the poor and homeless with food and other services. Obama handed them pre-assembled lunch plates of chicken, potato salad, mixed vegetables and bread.

He brought the whole family: first lady Michelle Obama, daughters Malia and Sasha, mother-in-law Marian Robinson and some aides.