Fifty years ago, the White House was the site of an unusual party.
It was a celebration of the Emancipation Proclamation's centennial, held on Abraham Lincoln's birthday, and many of the guests were descendants of the people Lincoln's historic document freed.
But noticeably absent was the Rev. Martin Luther King Jr. The civil rights leader had declined the invitation after earlier conversations with President Kennedy about segregation had yielded few results.
This weekend, hundreds of thousands of people — including President Obama and his family — are participating in volunteer activities around the country. Saturday's National Day of Service kicks off the president's second inauguration and honors the Rev. Martin Luther King Jr.'s birthday.
As budgets tighten and personal schedules fill, nonprofits are looking for new ways to attract extra helpers, and organizers for the national event hope it will lead to a permanent boost in volunteerism.