"I want to serve, I'm ready to serve," said Juan Perez, 20, a Garden City, Kan., volunteer who works from a wheelchair because of muscular dystrophy. He also won't be able to spend another year tutoring Spanish-speaking children unless Congress increases the program's funding.
The rally, which began in a Senate office building and was to run around-the-clock through Saturday afternoon, will feature more than 600 speakers - lawmakers, AmeriCorps alumni, university professors and representatives from nonprofit organizations.
Along with more money to rescue hundreds of foundering local programs this year, supporters want Congress to meet President Bush's 2004 proposal to more than double membership.
Bush's 2004 request of $444 million would fund 75,000 members.
About 30,000 volunteers were enrolled this year, down from 67,000 last year. The House voted in July to provide only $355 million next year - still above current levels - while House Republican leaders rejected a Senate effort to add $100 million to the program this year.
"AmeriCorps has been mismanaged for years and the last thing they need is more money. They need fundamental reform," said John Schofield, a House Appropriations Committee spokesman.
Last year, AmeriCorps approved more volunteers than its educational trust could support, forcing Congress to direct money away from service programs to make up for the shortfall. The inspector general for the Corporation for National and Community Service, which runs AmeriCorps, determined earlier this year that poor management was partly to blame for the enrollment miscalculations.
Michael Brown, president and co-founder of the think tank and service organization City Year, blames the problems with AmeriCorps on what he calls a glitch at the Federal level.
"A large part of the glitch is that so many Americans wanted to serve," said Brown, in an interview with CBS News. "What we're saying is that we need to say 'yes' to all those who want to serve."
"Our hope is that [Congress] will follow suit with the Senate and pass the $100 million and keep America serving."
Letters in support of an emergency flow of cash to the popular program have come from majorities in the House and Senate, 147 mayors and 44 governors, including the president's brother, Gov. Jeb Bush of Florida.