McCarthy, a former AFL-CIO vice president, said he appreciated Tolman's support.
"He believes I'm the person to succeed him on Beacon Hill," McCarthy said. "I'm proud and honored to receive his endorsement and continue his legacy."
McCarthy, who served as a Watertown firefighter for 34 years, retired in 2001 and went on to become the vice president of the AFL-CIO for 10 years. He also served as president of the Professional Fire Fighters of Massachusetts for 23 years until he stepped down in January 2011. He served in the U.S. Navy from 1966 to 1968.
Tolman said he and McCarthy both attended the same high school in Watertown a few years apart, and that they both went through the Harvard Trade Union Program together in 1980.
"He was unanimously endorsed by the AFL-CIO's executive board of 61 members," Tolman said. "He is not a carbon copy. He will stand up for his district."
As part of his campaign, McCarthy has pledged to serve no more than two terms if elected, and to donate half of his senatorial salary to programs for seniors and children.
"I want to get the message out there that we're trying to work with and help those people wherever and whenever we can," McCarthy said. "This is not a career for me, this is not a money issue for me, this is not to do my resume up. I am here to give people a voice who need a voice and don’t have a voice."
Tim Schofield, a Brighton resident and attorney also running on the Senate ticket, today received an endorsement from Ayanna Pressley, the top vote-getter in the recent elections for Boston City Council.
Schofield also has received endorsements from state Reps. Michael Moran and Kevin Honan, both Brighton Democrats, as well as Boston City Councilors John Connolly, Michael Ross, Matt O'Malley, and Mark Ciommo.