With his own hands, Obama helped renovate the temporary shelter in the upstairs part of the home, a project designed to install curtains, lockers and energy-efficient light fixtures, according to a spokesman for the inauguration committee.

After that, he stopped at Calvin Coolidge High School greeting over 300 volunteers who were busy sending letters to troops.

"Both of us participated in service this morning," Obama said standing next to his wife Michelle.

"It is fitting that all of you and hundreds of thousands, maybe more than a million, people, through 11,000 service projects all across the country, today commemorated Dr. King and got involved in this process of remaking America," he said.

Some fellow politicians in Washington followed Obama's call for service.

U.S. President-elect Barack Obama paints drawers and cabinets in a room at Sasha Bruce House, an emergency shelter for teens in Washington, January 19, 2009. [Xinhua/Reuters]

Rep. John Sarbanes , a second-term Democrat from Maryland, offered his service at Anacostia Park in Washington to promote environmental education for kids.

Throughout the day, memorial services were held across the country to commemorate King.

In King's hometown in Atlanta, Ga., some 2,000 people gathered in Ebenezer Baptist Church where King once preached, to pay tribute to the civil rights icon.

Isaac Newton Farris, King's nephew, linked Obama's presidency to King, saying Obama's inauguration was built on a legacy of King.

But he also cautioned that despite the historic importance of the fact that Obama will become the first African-American to hold the highest office of the nation, King's dream of eliminating disparities in health care, education and economics hasn't been fulfilled.

Former Secretary of State Colin Powell also expressed similar views when attending a breakfast in Minneapolis, Minn., to honor Martin Luther King.

Powell, who made history in his own merit to become the country 's first black secretary of state, said Obama's inauguration is a tribute to the memory of King.

"We must all come together to support our new president in who we have placed such hope and such expectation," he added.

Although Obama had no contact with King and was only a child when King was assassinated in 1968, but the president-elect has long been tapping into King's legacy in his political career.

Throughout his presidential campaign, he repeatedly invoked King's words to inspire his supporters.

He also accepted the Democratic presidential nomination on Aug. 28, 2008, the 40th anniversary of King's famous "I Have a Dream" speech

(Xinhua News Agency January 20, 2009)