Judge William Hancock of the King's Court presided at the courthouse. He was later unintentionally killed by the British in the American Revolution 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.
Salem County is also notable for its distinctive Quaker-inspired architecture and masonry styles of the 1700s.
As of the census of 2000, there were 64,285 people, 24,295 households, and 17,370 families residing in the county. The population density was 190 people per square mile (73/km²). There were 26,158 housing units at an average density of 77 per square mile (30/km²). The racial makeup of the county was 81.19% White, 14.77% Black or African American, 0.35% Native American, 0.62% Asian, 0.03% Pacific Islander, 1.57% from other races, and 1.46% from two or more races. 3.89% of the population were Hispanic or Latino of any race. 16.0% were of German, 13.2% Irish, 12.8% Italian, 11.1% English and 7.7% American ancestry according to Census 2000.
There were 24,295 households out of which 32.40% had children under the age of 18 living with them, 53.80% were married couples living together, 13.30% had a female householder with no husband present, and 28.50% were non-families. 24.30% of all households were made up of individuals and 10.60% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 3.08.
In the county the population was spread out with 25.60% under the age of 18, 7.80% from 18 to 24, 27.90% from 25 to 44, 24.20% from 45 to 64, and 14.50% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 93.40 males. For every 100 females age 18 and over, there were 90.20 males.
The median income for a household in the county was $45,573, and the median income for a family was $54,890. Males had a median income of $41,860 versus $27,209 for females. The per capita income for the county was $20,874. About 7.20% of families and 9.50% of the population were below the poverty line, including 13.30% of those under age 18 and 6.60% of those age 65 or over.