Booker announced the figure in an email to supporters. Booker's sum puts him near the back of the pack in fundraising. Of those candidates that have announced their figures, only entrepreneur Andrew Yang announced raising less than Booker.
Former Texas congressman Beto O'Rourke raised $6.1 million during his first 24 hours of presidential campaigning beginning March 14, edging Bernie Sanders' $5.9 million over the same period to top the Democratic field.
Booker noted that 82% of his contributions came from people that had never contributed to his campaign before. Booker said Sunday he feels "incredible" about the fundraising haul.
Pete Buttigieg (BOO'-tuh-juhj) is defending his experience ahead of an expected run for president, saying he isn't someone who has "been marinating in Washington" for a long time.
Asked on Sunday on "Meet the Press" about his qualifications, the mayor of South Bend, Indiana, says he'd "stack up my experience against anybody," though he acknowledged "it's not as traditional."
The Democratic field is full of senators and members of the House.
Buttigieg says "being a mayor of a city of any size means that you have to deal with the kinds of issues that really hit Americans."
Buttigieg isn't confirming that he plans to announce his candidacy at an event next Sunday in South Bend but says "the kind of thing we're going to announce is the kind of thing you only get to announce once."
Democratic presidential candidate Cory Booker is campaigning in New Hampshire and promoting a program known as baby bonds.
It calls for newborns to get a savings account. The government would contribute up to $2,000 to the account annually until the child is 18. The amount would depend on their parents' income.
Booker's campaign says it's expected that one in 10 kids in New Hampshire would receive the full $2,000 contribution annually.
The New Jersey senator says the plan would let kids use the fund to get training, to go to college, to start a business or to buy a home.
Booker says the idea is to "create a fair playing field where everybody has a stake in this economy."
Following all directions on the compass, the Democrats who want to make Donald Trump a one-term president are resuming their efforts to convince voters they have what it takes to lead the country.
That's why Bernie Sanders, the Vermont senator, and Beto O'Rourke, a former Texas congressman, are campaigning Sunday in Iowa.
John Hickenlooper, a former Colorado governor, is promoting his candidacy in South Carolina. Cory Booker, the New Jersey senator, has stops in New Hampshire.
Amy Klobuchar (KLOH'-buh-shar), the Minnesota senator, is making a pitch to voters in Las Vegas.
The Democratic field has more than a dozen hopefuls, and other politicians are considering jumping in.
Michael Bennet, the Colorado senator recently diagnosed with prostate cancer, is in New Hampshire as he decides on a White House run.