Salem County is a county located in the U.S. state of New Jersey. Its county seat is Salem city. The county is part of the Delaware Valley area. As of the 2010 Census, the county's population was 66,083, increasing by 1,798 (+2.8%) from the 64,285 counted in the 2000 Census, retaining its position as the state's least populous county. The most populous place was Middletown Township, with 13,409 residents at the time of the 2010 Census, while Lower Alloways Creek Township, covered , the largest total area of any municipality.
While a court was established in the area in 1681, Salem County was first formally established within West Jersey on May 17, 1694, from the Salem Tenth. Pittsgrove Township was transferred to Cumberland County in April 1867, but was restored to Salem County in February 1868.
The Old Salem County Courthouse, situated on the same block as the Salem County Courthouse, serves as the court for Salem City. It is the oldest active courthouse in New Jersey and is the second oldest courthouse in continuous use in the United States, the oldest being King William County Courthouse (1725) in Virginia. The courthouse was built in 1735 during the reign of King George II using locally manufactured bricks. The building was enlarged in 1817 and additionally enlarged and remodeled in 1908. Its distinctive bell tower is essentially unchanged and the original bell sits in the courtroom.
Judge William Hancock of the King's Court presided at the courthouse. He was later unintentionally killed by the British in the American Revolutionary War during the massacre of Hancock House committed by the British against local militia during the Salem Raid in 1778. The courthouse was afterwards the scene of the "treason trials," wherein suspected Loyalists were put on trial for having allegedly aided the British during the Salem Raid. Four men were convicted and sentenced to death for treason; however, they were pardoned by Governor William Livingston and exiled from New Jersey. The courthouse is also the site of the legend of Colonel Robert Gibbon Johnson proving the edibility of the tomato. Before 1820, Americans often assumed tomatoes were poisonous. In 1820, Colonel Johnson, according to legend, stood upon the courthouse steps and ate tomatoes in front of a large amazed crowd assembled to watch him do so.