Monmouth County is a county located in the U.S. state of New Jersey, within the New York metropolitan area. As of the 2010 Census, the population was 630,380, up from 615,301 at the 2000 Census, making it the fifth-most populous county in the state. Its county seat is Freehold Borough. The most populous municipality was Middletown Township with 66,522 residents at the time of the 2010 Census.
Monmouth County ranked 38th among the highest-income counties in the United States as of 2011, placing it among the top 2% of counties by wealth. As of 2009, it was ranked 56th in the United States by personal per-capita income. On October 29, 2012 Hurricane Sandy caused catastrophic damage to coastal areas of Monmouth County. As Sandy's surge arrived in Monmouth County flood levels of 13.31 feet above normal were measured at Sandy Hook shortly before the destruction of the tidal station, breaking all previous local records. The surge caused waves as high as 32.5 feet measured where the Sandy Hook Bay meets the New York Bay.
"It was Hendrik Hudson and his crew aboard the Dutch vessel 'Half Moon" who, in 1609, first spotted land in what is now Monmouth County, most likely off Sandy Hook. Among the first European settlers in the area were a group of Scots settled in Freehold Township in about 1682-85, followed several years later by Dutch settlers. As they arrived in this area, they were greeted by Lenape Native Americans, who lived in scattered small family bands and developed a largely amicable relationship with the new arrivals.
Monmouth County was established in 1675. Its name may come from the Rhode Island Monmouth Society or from a suggestion from Colonel Lewis Morris that the county should be named after Monmouthshire in Wales, Great Britain. Other suggestions include that it was named for James Scott, 1st Duke of Monmouth (1649–1685), who had many allies among the East Jersey leadership. In 1714, the first county government was established.
At the June 28, 1778, Battle of Monmouth, near Freehold, General George Washington's soldiers battled the British under Sir Henry Clinton, in the longest land battle of the American Revolutionary War. It was at Monmouth that the tactics and training from Friedrich Wilhelm von Steuben developed at Valley Forge during the winter encampment were first implemented on a large scale.