Watervliet is a city in Albany County in the U.S. state of New York. The population was 10,254 as of the 2010 census. Watervliet is north of Albany, the capital of the state, and is bordered on the north, west, and south by the town of Colonie. The city is also known as "the Arsenal City". The explorer Henry Hudson arrived in the area of Watervliet around 1609. The area was first settled in 1643 as part of the Rensselaerswyckpatroonship, under the direction of Kiliaen van Rensselaer. In 1710, Derrick van der Heyden operated a ferry from the Bleeker Farm (near 16th Street) across the Hudson River to Troy. Troops during the Revolutionary War used this ferry in 1777 on their way to Bemis Heights and Stillwater for the Battle of Saratoga. In 1786, a second ferry was started at Ferry Street (today 14th Street) over to Troy. The town of Watervliet was founded in 1788 and included all of present-day Albany County except what was in the city of Albany at the time. Because so many towns had been created from the town of Watervliet, it is regarded as the "mother of towns" in the county. In 1816, as the first post office was erected, corner of River and Ferry streets (Broadway and 14th Street), it took the name Watervliet.