Green was born in Worcester, Massachusetts on October 6, 1820, one of 11 children. In 1835, he moved to New York, where two of his sisters ran a school for young girls. Green is the brother of Samuel Fisk Green, a medical missionary of the American Ceylon Mission in Sri Lanka.
Green started work in the mercantile trade and befriended a local merchant, who subsequently hired him to manage his sugar refining plantation in Trinidad. Green lived there for about a year, where he kept a daily diary of his thoughts.
Green returned to Worcester for a year or two before returning to New York City to pursue a legal career.
In 1845, Green became a lawyer under the tutelage of railroad attorney Samuel J. Tilden. The two met at a party and became fast friends, along with Tilden's law partner John Bigelow. In 1854, Green was elected to the New York City Board of Education. He soon became its president a year later.
From 1857 to 1870, Green was active in or led the Central Park Commission. The Republican-led New York State Legislature began to institute measures to control the municipal affairs of the largely Democratic metropolitan region; one such act created the Central Park Commission (CPC). Green was appointed to the CPC, eventually becoming its head. A year later Olmsted and Vaux's Greensward Plan for Central Park was chosen by the CPC, thanks largely to Green's influence. The CPC's work would proceed under Green's leadership, despite resistance from resentful local Tammany Hall politicians who had little control of the project.
With Green's coaxing, the legislature began to expand the CPC's authority, transforming it into the city's first comprehensive planning body. In the next decade, the CPC planned and/or proposed improvements in northern Manhattan, the Harlem River, and the Bronx. Projects included Riverside, Morningside and Ft. Washington Parks; the street plan above 155 Street; a widened and straightened Broadway; a Grand Circle at 59th Street and Eighth Avenue, and more. In 1869, Green got approval for the CPC to create the American Museum of Natural History, and the Metropolitan Museum of Art, two public-private institutions.
By 1870, a new home-rule ("Tweed") charter ended the state-run CPC. However, the city's Departments of Public Works and Public Parks would eventually execute most of the CPC's unfinished plans. The Tweed Ring was exposed in 1870, and Green was made New York City Comptroller to sort out the ring's crippling theft and graft. He used his personal credit to obtain funds to cover the city payroll. He cut waste and halted most public works to spare the city from bankruptcy. Critics claimed his retrenchment policy was too arbitrary and severe. Green served until 1876. Later, the Niagara (Falls) Park Commission was created to establish New York's first state park and defend the falls; Green soon became president of the commission and would serve until his death.
In 1886, Samuel J. Tilden died, leaving a fortune to create a public library for New York City, but his will was contested by relatives. The executors, Green and two others, had to make do with fewer funds. Green would propose consolidating the Tilden Trust with the Astor and Lenox Libraries, leading eventually to the New York Public Library.
Green was elected a member of the American Antiquarian Society in 1889.
Sentiment soon built in the business community for municipal consolidation of the metropolitan region to protect the mismanaged port. The state legislature created a commission to explore consolidation, with Green at its head. Green immediately proposed an ambitious consolidation plan that would be rebuffed a number of times, mostly by Brooklynites who called the movement "Green's hobby." In 1894, changing his approach, Green got a nonbinding consolidation referendum on the ballot. Most surrounding municipalities voted in favor of consolidation, but Brooklyn's pro-consolidation majority was razor thin. only about 0.2%. Alarmed by the results, opponents lobbied to thwart subsequent bills by Green and others.
Also in 1894, Green also rallied preservation-minded New Yorkers against the proposed demolition of the 1812 New York City Hall building. The following year, he formed the city's first formal preservation and conservation group, called the American Scenic and Historic Preservation Society. The society created parks and fought to rescue endangered sites throughout New York City and State; it became defunct in the 1970s. Green became President of the New York Zoological Society, as well, serving from 1895-97.
Republican Party boss Thomas C. Platt embraced Green's consolidation plan, and pushed the measure through the legislature in 1896; a Greater New York charter was passed in 1897.
On November 13, 1903, Green was murdered at his home at Park Avenue and 40th Street, in a case of mistaken identity. He was buried in Worcester, Massachusetts. In 1905, his family estate in that city was turned into a public park.
Several memorials have been erected for Green. In 1929, a memorial bench was dedicated to him in Central Park; It was surrounded by five elms, representing the five boroughs. In the 1980s, the bench was moved to another hill at 40.79512°N 73.95428°W / 40.79512; -73.95428, overlooking Harlem Meer, and new maples were planted in 1998. Bath Island in the Niagara River was renamed Green Island in his honor. In 2010, Andrew Haswell Green Park was named on Manhattan's East Side.
Green and his extensive contributions to New York City are the subject of a recent biography by Michael Rubbinaccio entitled "New York's Father is Murdered! The life and death of Andrew Haswell Green." Rubbinaccio's book presents evidence that Green, not John Bigelow, was the "founder" of the New York Public Library.