Erin Murphy, one of more than a dozen candidates seeking four at-large slots on the City Council, has picked up the endorsement of District 3 Councillor Frank Baker.

Murphy, a longtime Boston Public Schools teacher, had previously garnered endorsements from state Rep. Dan Hunt of Dorchester and unions ranging from the Massachusetts Nurses Association, Boston Firefighters Local 718, Laborers Local 223, to Boston EMS.

Baker, elected to the council in 2011, represents much of Dorchester on the 13-member body.

“Anyone who can wrangle a roomful of kindergartners has a head start on serving in government,” Baker said in a statement on his endorsement. “Erin’s commitment to public service is second-to-none, and she would be a major asset for the whole city.”

Murphy and Baker plan to campaign together ahead of the Sept. 14 preliminary, which will narrow the field of at-large candidates to eight before the November final election.

Baker is facing his own challenger in Stephen McBride, who works as a manager at the marketing firm HubSpot.