In 1683, nineteen years after the Dutch surrendered New Amsterdam to the English, two New York City merchants, Frances Rombout and Gulian Verplanck, purchased 85,000 acres in Dutchess County from the Wappinger Indians for a quantity of rum, powder, cloth, hatchets, shirts, knives, bottles, white wampum, earthen jugs and 80 pounds of tobacco. Rombout and Verplanck never lived on their land, intending to use it only for fur trading. The first white settlers were Rombout's daughter, Catharyna and her husband, Roger Brett, who built a mill at the mouth of the Fishkill Creek as it flows into the Hudson. Their house, built about 1709, still stands in Beacon, and is the oldest continuous residence in Dutchess County. The name Fishkill is derived from two Dutch words: Vis (fish) and Kill (creek or stream).
Fishkill played an important role in the Revolutionary War when a vast military encampment was established one mile below the village to guard the mountain pass to the south. Signal fires lay in readiness on tops of the surrounding mountains. The Fishkill encampment became the main supply depot for the northern division of the Continental Army. The first 1,000 copies of the New York State Constitution were turned out on Samuel Loudon's press at Fishkill in 1777. Trinity Episcopal Church became a hospital for soldiers recovering from smallpox, and the Dutch Reformed Church was used as a military prison.
During the 19th century mills and factories sprang up in Glenham and Matteawan. The Glenham Woolen Mill, which brought an influx of skilled weavers from the British Isles, made the hamlet of Glenham a busy industrial center. The healthy economy enjoyed by the mills came to an end in the post-Civil War depression and the once thriving factories fell into decay. New life came in 1931 when Texaco purchased the old woolen mill site and established a research center there. Today, the town's industry is technology based and the farmland has been converted to residential housing. But the beauty of the area continues to attract new people, diversified businesses and tourists.