Four of the five living presidents will wish AmeriCorps a happy birthday.

Four of the five living presidents will wish AmeriCorps a happy birthday. George W. Bush Center

AmeriCorps Is Almost Old Enough to Drink

The national service organization turns 20 this year, and three ex-presidents will join President Obama to say, "Happy Birthday."

Like many of its volunteers, AmeriCorps is almost 20 years old.

Three of the four living ex-presidents will join President Obama – two from afar – in celebrating the national service organization's 20th birthday on Thursday, the White House said.

Former President Bill Clinton will speak with Obama on the south lawn of the White House, while 90-year-old former President George H. W. Bush will participate in a pledge ceremony marking the occasion from his home in Kennebunkport, Maine. The younger President Bush has filmed a video that will be played at dozens of ceremonies across the country.

In a statement Tuesday, the White House noted the role that each of the leaders played in creating and expanding AmeriCorps, in which more than 900,000 Americans have served in the last 20 years.

The elder President Bush signed legislation in 1990 creating precursors to AmeriCorps, while President Clinton in 1994 signed the bill that actually formed the program. President George W. Bush expanded the initiative by 25,000 volunteers after the terrorist attacks of Sept. 11, 2001, and President Obama built it out even more in several pieces of legislation and executive actions.

Wendy Spencer, the CEO of the agency that administers AmeriCorps, said the program had been "a remarkable force for good" over the last 20 years.

The participation of four presidents in this nationwide pledge ceremony is a testament to the value of AmeriCorps and its indispensable role in solving problems, strengthening communities, and expanding economic opportunity.”

The White House said that since its inception, AmeriCorps volunteers have performed more than 1.2 billion hours of service and earned more than $2.7 billion in educational scholarships through the program.