[2] Harrison was established in 1696 by a patent granted by the British government to John Harrison and three others, who had a year earlier bargained with local Native Americans to purchase an area of land above Westchester Path, an old trail that led from Manhattan to Port Chester and below Rye Lake.

[4] In fact, the land below Westchester Path and along Long Island Sound had already been purchased and partly developed by the settlers of Rye, New York.

The area that became Harrison had also been sold in 1661 or 1662, and again in 1666, to Peter Disbrow, John Budd, and other investors or early residents of Rye.

[5] Disbrow and Budd evidently lost their paperwork and the land was ultimately granted to Harrison and his co-investors in 1696.

[4][7] Harrison's Purchase was administered jointly by the settlers of Rye until it was incorporated as a town on March 7, 1788, by an act of the New York State legislature.

[8] Merritt's Hill in West Harrison was the site of the Battle of White Plains during the Revolutionary War.

In 1875, Sunny Ridge farm mansion was renovated to include a 14th-century woodcut from Europe, installed into the wall over the living room fireplace, among several other ancient relics, built into the home.

What is the present-day Metro-North Railroad's New Haven Line, running from Manhattan in New York City, to Greenwich, Connecticut, first came through Harrison in 1848, though the first station was not built until 1870.

The same year, Harrison's former Sunnyridge Farm, located less than a half mile from the train station, was purchased by real estate developer Sidney H. Sonn, of H. & S. Sonn Co., based in New York City, and subdivided into lots for a real estate development.

According to a 1928 article in The New York Times, "[H. & S. Sonn] virtually transformed their part of the old farm into a park, installed winding tree-lined motorways and water, gas, sewers, and electricity, and landscaped the entire 165 acres, then they erected ten English-type houses which were designed by Julius Gregory, one of them being completely furnished by Charles of London.

Lane; musical star Louise Groody; and Fitzhugh Green, of Putnam's Publishing House, among the first residents of the new neighborhood.

[9] Sidney Sonn renovated the farm's original house, an immense, elaborate, 20-room, 1875 Victorian mansion, into an English Tudor, designed by renowned architect Julius Gregory, father of the American Tudor-Revival style and movement of the 1920s, as a residence for himself.

Re-elected eight times, he served until 1983 when he resigned to become Commissioner of the New York State Department of Motor Vehicles.

Creatively, to avoid being served papers that would have begun the legal proceedings for Purchase to incorporate as a village, Passidomo entered his office through the fire escape.

The distance from Harrison Station to Grand Central Terminal in Midtown Manhattan is about 27 miles (43 km).

The New England Thruway (I-95) runs through the town (without any interchanges), as well as the Cross Westchester Expressway and the Hutchinson River Parkway.

West Harrison contains the Passidomo Veterans Memorial Park and Pool and the Leo Mintzer Center.

[17] Downtown is split into the four sections mentioned above, and is flanked by Interstate 95, the Hutchinson River Parkway, and the Metro-North Railroad.

The "Downtown" with Halstead Ave as the main thoroughfare, starting on the City of Rye border, is parallel to the Metro North railroad, delivers traffic into the Village of Mamaroneck.

Flanking Halstead Ave are streets consisting of older two- family homes with new duplexes gentrifing the community.

[citation needed] On June 22, 2023, Harrison agreed to settle an employment discrimination lawsuit brought by the Justice Department.

The $450,000 settlement is one of the largest payments by a municipality in an employment discrimination case brought by the United States on behalf of a single individual.