Former Vice President Joe Biden's campaign announced Wednesday that he raised $21.5 million since launching his bid for the White House in April.

According to his campaign, in 66 days, they received 436,000 donations from 256,000 donors. The campaign also said 97% of donations were from grassroots supporters and under $200. The average donation was $49.

The campaign claims Biden raised more money per day than any other presidential candidate, an estimate based on the per-day average of donations since he announced his run for the presidency. The former vice president's campaign also raised $6.3 million in its first 24 hours.

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"After just two months in this race, we have seen Americans in every corner of the country chip in to join this battle for the soul of our nation," said campaign manager Greg Schultz in a statement. "We are grateful for the immense grassroots support we are seeing. We're continuing to build a campaign that energizes and expands Team Joe and puts us in a strong position to take on Donald Trump."

South Bend Mayor Pete Buttigieg, another candidate for the Democratic presidential nomination, announced Monday that he had raised $24.8 million in the second quarter despite lagging behind Biden in the polls. Biden, however, did raise more than Sen. Bernie Sanders, who raised $18 million in the second quarter from nearly one million donations.

Sanders, who transferred another $6 million to his campaign from other accounts, has made it a point to call out Biden and Buttigieg for attending high-dollar fundraisers while he focuses solely on grassroots efforts. Since launching his bid, Biden has held a series of high-dollar fundraisers across the country, including ones in New York, California, Illinois, Texas, South Carolina, Tennessee, Florida, Massachusetts, Georgia, Maryland, Washington state and Washington, D.C.

In recent weeks, Biden has faced some backlash over a series of comments made at fundraisers, including remarks he made about working with segregationists in the Senate. When Sen. Kamala Harris confronted him about his stance on busing last week, it became one of the most talked about moments of the first Democratic presidential debate.

Despite taking heat from opponents, Biden continues to hang onto his lead in recent polls conducted after the debates, including ones from CNN, Quinnipiac and the Washington Post.

All presidential candidates are required to file their second quarter fundraising with the Federal Election Commission by July 15th.