Surrounded by supporters on the steps of City Hall Sunday, Jackson, who serves as the chair of the council's education committee, painted himself as a tireless fighter with a long track record of working to improve public schools.
"Today, with a commitment to be an advocate for our children, a fighter for our neighborhoods, and an energetic leader for Manhattan, I am officially announcing my candidacy to be the next Borough President of Manhattan!" Jackson told the crowd to loud applause.
Jackson, who famously walked from New York City to Albany to secure state funding for city schools, is barred from running for his council seat again because of term limits.
In his remarks, Jackson, standing in a sea of blue-and-white supportive placards, stressed his experience on the council of listening to families, working with teachers and students, and helping to negotiate budget and land-use deals.
"I am a council leader...who has taken on the tough fight and not backed down and gotten results for the people of New York City," Jackson, who lives in Washington Heights, said.
Jackson has raised about $280,000 so far for his bid to succeed current Borough President Scott Stringer, who is leaving the post to run for comptroller.
Still, Jackson is facing a crowded field of challengers, including former Community Board 1 Chairwoman Julie Menin, East Side City Councilwoman Jessica Lappin and Upper West Side City Councilwoman Gale Brewer.
Menin, who began aggressively fundraising more than a year ago, has raised more than $1 million, according to city records. She has also snagged endorsements from officials including former Mayor Ed Koch, State Sen. Adriano Espaillat, former Public Advocate Betsy Gotbaum and former Manhattan Borough President C. Virginia Fields.
Lappin, meanwhile, has raised nearly $684,00, city records show, and has been endorsed by a host of East Side pols, including Rep. Carolyn Maloney, State Sen. Liz Krueger, and Assemblymen Micah Kellner and Dan Quart.
Brewer has yet to ramp up her fundraising efforts or officially declare her candidacy.