ABC News' Catherine E. Ake reports:

WASHINGTON - Hollywood actress Jennifer Garner may be one of America's most glamorous stars, but growing up in rural West Virginia has given her a heart for America's underprivileged children.

Garner joined Health and Human Services Secretary Kathleen Sebelius and Education Secretary Arne Duncan at an online rally Monday attended by several advocacy groups working on behalf of children aged 0-5 to push for more government funding for programs that help the youngest children.

"You don't know what early childhood education is … its patty-cake," Garner said at the Rally 4 Babies online conference hosted by the non-profit organization Zero to Three. "There's not a day in the world that we don't sing Laurie Berkner songs in my house … but that's because it was modeled for me. My mom did it to me, she sang to me, so I sing to my babies."

(Getty Images)

Garner, a mother of three, lent her celebrity to the issue at a time when the government's financial resources are threatened by sequestration and large scale budget cuts. Automatic sequestration cuts are currently slated to slash more than $400 million from the Head Start program's budget, or the equivalent of cutting 70,000 children from the program, which gives low income kids access to early childhood education.

At the conference, Duncan called on Congress to move forward with President Obama's proposal to invest $100 billion in programs for children aged 0-5, a proposal he called "the ultimate long-term investment."

"The dividends we won't necessarily see for another 10 or 15 or 20 years, but if we invest early, the dividends for society are tremendous," Duncan said. "Less dropouts, less teenage pregnancy, less crime, more graduates, more people working, more people becoming productive tax payers contributing to society."

Advocates say that giving all babies a stronger start will bridge the gap between economically disadvantaged children and those from more privileged backgrounds. They argue that investing more money in a child's early years, and ensuring his intellectual base, will increase his success, lowering financial and social concerns in the future.

"I see the difference in the kids' faces," said Garner, who is an artist ambassador for the child advocacy group, Save the Children. "I get so excited to see the mom feel connected to her baby, and the baby come alive … and become more verbal, and more, more curious, and more awake and aware."

"And it just makes me more and more passionate," she added.