Bergen County is the most populous county in the U.S. state of New Jersey. As of the 2010 United States Census, its population was 905,116, an increase of 20,998 (2.4%) from the 884,118 enumerated in the 2000 Census; as of 2013, the county's population was estimated to have increased by 2.2% since 2010, to 925,328. Located in the northeastern corner of New Jersey and its Gateway Region, Bergen County is part of the New York City Metropolitan Area and is situated directly across the George Washington Bridge from Manhattan.
Bergen County's population resides among 70 municipalities, but no large cities – its most populous place, with 43,010 residents at the time of the 2010 Census, is Hackensack, also its county seat; while Mahwah covered , the largest total area of any municipality.
Bergen County is one of the wealthiest counties in the United States, with a median household income of $81,708 per the 2010 Census, increasing to an estimated $84,255 in 2012. The county hosts an extensive park system totaling nearly .
At the time of first European contact, Bergen County was inhabited by Native American people, particularly the Lenape Nation, whose sub-groups included the Tappan, Hackensack, and Rumachenanck (later called the Haverstraw), as named by the Dutch colonists. Some of their descendants are included among the Ramapough Mountain Indians, recognized as a tribe by the state in 1980. Their ancestors had moved into the mountains to escape encroachment by Dutch and English colonists. Their descendants reside mostly in the northwest of the county, in nearby Passaic County and in Rockland County, New York, tracing their Lenape ancestry to speakers of the Munsee language, one of three major dialects of their language. Over the years, they absorbed other ethnicities by intermarriage.
In the 17th century, the Dutch considered the area comprising today's Bergen and Hudson counties as part of New Netherland, their colonial province of the Dutch Republic. The Dutch claimed it after Henry Hudson (sailing for the Dutch East India Company) explored Newark Bay and anchored his ship at Weehawken Cove in 1609. From an early date, the Dutch began to import African slaves to fill their labor needs. Bergen County eventually was the largest slaveholding county in the state. The African slaves were used for labor at the ports to support shipping, as well as for domestic servants, trades, and farm labor.
Early settlement attempts by the Dutch included Pavonia (1633), Vriessendael (1640), and Achter Col (1642), but the Native Americans repelled these settlements in Kieft's War (1643–1645) and the Peach Tree War (1655–1660). European settlers returned to the western shores of the Hudson River in the 1660 formation of Bergen Township, which would become the first permanent European settlement in the territory of present-day New Jersey.
During the Second Anglo-Dutch War, on August 27, 1664, New Amsterdam's governor Peter Stuyvesant surrendered to the English Navy. The English organized the Province of New Jersey in 1665, later splitting the territory into East Jersey and West Jersey in 1674. On November 30, 1675, the settlement Bergen and surrounding plantations and settlements were called Bergen County in an act passed by the province's General Assembly. In 1683, Bergen (along with the three other original counties of East Jersey) was officially recognized as an independent county by the Provincial Assembly.
Initially, Bergen County consisted of only the land between the Hudson River and the Hackensack River, extending north to the border between East Jersey and New York. In January 1709, the boundaries were extended to include all of the current territory of Hudson County (formed in 1840) and portions of the current territory of Passaic County (formed in 1837). The 1709 borders were described as follows:
Bergen was the location of several battles and troop movements during the American Revolutionary War. Fort Lee's location on the bluffs of the New Jersey Palisades, opposite Fort Washington in Manhattan, made it a strategic position during the war. In November 1776, the Battle of Fort Lee took place as part of a British plan to capture George Washington and to crush the Continental Army, whose forces were divided and located in Fort Lee and Hackensack. After abandoning the defenses in Fort Lee and leaving behind considerable supplies, the Continental forces staged a hasty retreat through present-day Englewood, Teaneck, and Bergenfield, and across the Hackensack River at New Bridge Landing, one of the few sites where the river was crossed by a bridge. They destroyed the bridge to delay the British assault on Washington's headquarters in village of Hackensack. The next day, George Washington retreated to Newark and left Hackensack via Polifly Road. British forces pursued, and Washington continued to retreat across New Jersey. The retreat allowed American forces to escape capture and regroup for subsequent successes against the British elsewhere in New Jersey later that winter. Soon after the Battle of Princeton in January 1777, British forces realized that they couldn't spread themselves thin across New Jersey. Local militia retook Hackensack and the rest of Bergen County. Bergen County saw skirmishes throughout the war as armies from both sides maneuvered across the countryside.
In 1837, Passaic County was formed from parts of Bergen and Essex counties. In 1840, Hudson County was formed from Bergen. These two divisions took roughly 13,000 residents (nearly half of the previous population) from the county's rolls.
In 1852, the Erie Railroad began operating major rail services from Jersey City on the Hudson River to points north and west via leased right-of-way in the county. This became known as the Erie Main Line, and is still in use for passenger service today.
In 1894, state law was changed to allow easy formation of municipalities with the Borough form of government. This led to the "boroughitis" phenomenon, in which many new municipalities were created in a span of a few years. There were 26 boroughs that were formed in the county in 1894 alone, with two more boroughs (and one new township) formed in 1895.
On January 11, 1917, the Kingsland Explosion took place at a munitions factory in what is today Lyndhurst. The explosion is believed to have been an act of sabotage by German agents, as the munitions in question were destined for Russia, part of the U.S.'s effort to supply allies before entrance into World War I. After the U.S. entry into the war in April 1917, Camp Merritt was created in eastern Bergen County for troop staging. Beginning operations in August 1917, it housed 50,000 soldiers at a time, staging them for deployment to Europe via Hoboken. Camp Merritt was decommissioned in November 1919.
The George Washington Bridge was completed in 1931, linking Fort Lee to Manhattan. This connection spurred rapid development in the post-World War II era, developing much of the county to suburban levels. Two lanes were added to the upper level in 1946 and a second deck of traffic on the bridge was completed in 1962, expanding its capacity to 14 lanes.
In 1955, the United States Army created a Nike Missile station at Campgaw Mountain (in the west of the county) for the defense of the New York Metropolitan Area from strategic bombers. In 1959, the site was upgraded to house Nike-Hercules Missiles with increased range, speed, and payload characteristics. The missile site closed in June 1971.
The prospect of property tax relief prompted County Executive Dennis McNerney to call in 2008 for municipalities with populations less than 10,000 in Bergen County to merge, saying "The surest way to significantly lower homeowners' property taxes is to merge small towns and reduce administrative overhead", with 35 of Bergen County's municipalities having less than 10,000 residents each.