But did you know that the volunteer movement was born right here in Philadelphia?
"I was working with then-Secretary of Labor and Industry Harris Wofford, a close colleague of Dr. King's," said Todd Bernstein, President of Global Citizen. "We talked about what it would be like if people across the nation would join forces, engage in a community-building process."
Bernstein says when Wofford represented Pennsylvania in the U.S. Senate, he teamed up with civil rights titan Congressman John Lewis and co-sponsored the King Holiday in Service Act in 1994. The goal was to get residents to serve their community on that day off.
So in 1996, Bernstein says the first King Day of Service kicked off right here in Philadelphia.
Action News was there as more than 1,000 volunteers in several dozen projects gave back to their neighbors.
More than 30 years later, the city's event is still billed as the largest in the U.S.
On Monday, Global Citizen organized service projects at Temple University
"And 2.7 million volunteers later. This has turned from a local project in Philadelphia into a national movement with hundreds and hundreds of projects throughout the nation," said Bernstein.