Westchester County grew from 24,000 people to a million as a pioneer suburb
When the first federal census counted Westchester County in 1790, about 24,000 people lived there. Railroads, an aqueduct and North America's first modern multi-lane parkway turned the farmland north of New York City into the world's first suburban area on such a scale, and in 2020 it passed a million residents.
Before Europeans arrived the land was part of Lenapehoking, home of the Lenape and of Wappinger bands such as the Siwanoy and Weckquaesgeek. Giovanni da Verrazzano passed by in 1524 and Henry Hudson in 1609, Dutch settlers came in the 1620s and English ones in the 1640s. Created in 1683 as one of New York's original twelve counties and named for Chester in England, it then included what is now the Bronx. By 1775 it was the colony's richest and most populous county, but during the Revolution it became the Neutral Ground, a lawless strip between British and Patriot lines, and the war left it wrecked.
Two projects in the 1800s set its future. The Croton Dam and Aqueduct, built from 1837 to 1842, is now a National Historic Landmark, and railroads arriving in the 1840s pulled population south toward the city; by 1860 the county had 99,000 people, with Yonkers the largest city. After the Civil War new fortunes built estates such as Lyndhurst, and factories lined the Hudson. The Bronx was peeled away in stages in 1874 and 1895.
The 20th century finished the transformation. The Bronx River Parkway, completed in 1925, encouraged whole new communities, and after the Second World War apartment blocks rose alongside single-family homes. The population reached 625,816 by 1950, and interstates and the Tappan Zee Bridge brought more growth. The Hudson there widens to 3.6 miles, its broadest point, a stretch colonists called the Tappan Zee.
Today White Plains is the county seat and Yonkers, with 211,569 residents, the biggest city. IBM, Mastercard and PepsiCo have headquarters there. Median household income reached $105,387 by 2021, and in 2013 its property taxes were the highest of any American county.
Source: Westchester County, New York
