It is located on the eastern side of the county and is adjacent to the Hudson River and the City of Newburgh.

Settlement rights in the area that now encompasses the town were obtained from the Munsee by Governor Thomas Dongan, who encouraged the settlement of a party of Scottish colonists led by David Toshack, the Laird of Monzievaird, and his brother-in-law Major Patrick McGregorie.

In June 1685, Governor Dongan appointed McGregorie Muster-Master of Militia for the City and Province of New York.

[2] A rival claim was obtained in 1694 by Captain John Evans of HMS Richmond, who was granted powers and privileges as lord of the manor.

[3] Around 1709, the portion of the town nearest the Hudson River was organized under the Precinct of the Highlands (Ulster County), remaining thus until 1743.

By whom this was conferred cannot be ascertained, but first appears in 1728 records of the London "Society for the Propagation of the Gospel in Foreign Parts".

This encampment or cantonment covered 1600 acres (6.5 km2) and quartered 6000–8000 men, women and children from New York, New Jersey, New Hampshire, Massachusetts and Maryland.

Here this army built a log city of over 700 huts for the soldiers and many other outbuildings, guardhouses, blacksmith shops, a stable, kitchens, and a hospital.

In an effort to preserve this encampment, the town of New Windsor acquired a 167-acre (0.68 km2) tract consisting of much of the former hut sites.

Since 1936, the town of New Windsor and the membership of the National Temple Hill Association have striven to ensure the preservation of this, the final winter encampment.

[citation needed] The Little Britain Presbyterian Church was organized by Irish and Scottish immigrants.

Circa 1858 to 1859, the Palmer and Longking company operated on the Quassaick Creek the first large scale factory for the manufacture of "bellows-box" daguerreotype cameras.

The eastern town line, marked by the Hudson River, is the border of Dutchess County.

New Windsor has a Dfa Köppen climate classification (humid continental: hot summer subtype).

The grand plan to create a jetport lead to the acquisition of over 8000 acres (32 km2) of the present day buffer zone and the loss of many early farms and structures.

Today, Stewart International in addition to its civilian capability, is the home base of the NY Air National Guard and United States Marine Corps Reserve MAG-49 Detachment Bravo.

Now for the first time, the airport can be accessed directly from the Interstates without encountering local traffic on the state roads.