On Thursday at the Smithsonian's National Museum of African art, there was a birthday party to celebrate "Mandela Day." Museum director Dr. Johnnetta Cole says her parents always had a saying about giving back that she relates to Mandela:
"Doing for others is just the rent you gotta pay for your room on earth. He paid serious rent! Can we not pay a little?"
Meanwhile, TransAfrica President Nicole Lee is the host of a citywide celebration and calls for a service Thursday night.
"It's a real unifying moment, a time of reflection, a time to think about the values of Nelson Mandela - what does he mean to us - and what does he expect - what does he expect of us," she explains.
On Thursday at D.C.'s Kingman Island on the Anacostia River, volunteers cleared invasive species from the bike and jogging paths near the fishing pier, honoring Mandela by serving D.C.'s environment in the spirit of volunteering.
Laura Washington of the D.C. Department of the Environment says, "Kingman Island is a DC-local forest and we try to do work to maintain the wildlife habitat here."
Officials from both Washington's city government and the South African Embassy participated.
Lucky Molefe, the Minister Counselor at the South African Embassy says:"Mandela Day is all about giving - it's a day of service. And it's about making a difference where you are with what you have."
Later on Thursday, a celebration on 16th and M Street placed the hundreds who assembled inside Metropolitan African Methodist Episcopal Church in the heart of South Africa to honor the man his nation affectionately calls, "Madiba."
On Nelson's Mandela's 95th birthday, the United Nations has declared July 18th "Nelson Mandela International Day" - and Congresswoman Barbara Lee says it's for an important reason.
"He showed us the way," she explains. "He showed us we could fight with our principles, he showed us reconciliation."
Former Congressman Ron Dellums recalls a former president who was encouraging and humble: "He looked at me and said, 'We have heard much of you, you gave us hope, you kept us alive.' And he hugged me."
While the South African people celebrate, a lung infection has kept Mandela in critical but stable condition. Still, family members tell ABC News that he is improving.
"I know what he's ailing from would've knocked people far younger than him, but it hasn't," says his granddaughter Ndileka Mandela.