Sen. Marco Rubio. (AP Photo/Molly Riley)

Sen. Marco Rubio (R-Fla.), off to a fast fundraising start as an official candidate for president, is planning an aggressive series of events to haul in cash in his home state in late April and early May, a person familiar with his campaign plans said Wednesday.

One of the events will involve billionaire businessman and philanthropist Norman Braman, who is expected to be one of Rubio's biggest financial backers, said the person, who was granted anonymity to describe behind-the-scenes planning.

That person also confirmed that Rubio raised about $1.25 million online on his first full day as a presidential candidate -- news first reported by the Associated Press.

Rubio will raise money in Palm Beach on April 24, in Miami on May 2 and in Boca Raton on May 12, the person said. Braman will be involved in the Miami event.

A Rubio spokesman declined to comment on fundraising.

Rubio, who launched his campaign on Monday, is seeking to stay in a competitive, crowded money chase in which rival Jeb Bush is expected to lead the pack, at least early on. Bush, the former Florida governor who is exploring a run, has already locked up many key donors in Florida and beyond.

Rubio's first-day online fundraising total roughly matched those of Sens. Ted Cruz (R-Tex.) and Rand Paul (R-Ky.), two other rivals who announced White House bids in recent weeks.

On Thursday, Rubio will raise money in New York and Boston. He will then hold fundraisers in Dallas on Monday and Houston on Tuesday, people familiar with the plans said. Those people were not authorized to speak on the record.

Ed O'Keefe contributed.