High Bridge was originally incorporated as a township by an Act of the New Jersey Legislature on March 29, 1871, from portions of both Clinton Township and Lebanon Township and Bethlehem Township. On February 19, 1898, the borough of High Bridge was incorporated from portions of the township, with the remainder returned to Clinton and Lebanon Townships.
High Bridge Borough is located on the South Branch of the Raritan River in the north central part of Hunterdon County. Water from the South Branch was a valuable power source for one of the first ironworks in the United States, established by William Allen and Joseph Turner of Philadelphia. Allen was the mayor of Philadelphia, a Chief Justice of Pennsylvania, and a prominent landowner in New Jersey. The Central Railroad of New Jersey built a high bridge across the river from which structure the locality ultimately took its name.
As of the census of 2000, there were 3,776 people, 1,428 households, and 1,051 families residing in the borough. The population density was 1,566.0 people per square mile (604.9/km²). There were 1,478 housing units at an average density of 613.0/sq mi (236.8/km²). The racial makeup of the borough was 96.24% White, 0.79% African American, 0.34% Native American, 1.43% Asian, 0.03% Pacific Islander, 0.45% from other races, and 0.72% from two or more races. Hispanic or Latino of any race were 2.12% of the population.
There were 1,428 households out of which 39.9% had children under the age of 18 living with them, 62.3% were married couples living together, 8.5% had a female householder with no husband present, and 26.4% were non-families. 20.9% of all households were made up of individuals and 4.8% had someone living alone who was 65 years of age or older. The average household size was 2.64 and the average family size was 3.10.
In the borough the population was spread out with 27.6% under the age of 18, 5.3% from 18 to 24, 36.4% from 25 to 44, 24.2% from 45 to 64, and 6.5% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 94.0 males. For every 100 females age 18 and over, there were 92.7 males.
The median income for a household in the borough was $68,719, and the median income for a family was $75,357. Males had a median income of $56,607 versus $35,450 for females. The per capita income for the borough was $29,276. About 1.9% of families and 3.2% of the population were below the poverty line, including 1.9% of those under age 18 and 9.2% of those age 65 or over.
The High Bridge station is the western terminus on New Jersey Transit's Raritan Valley Line. It is located at the southern end of the station. The parking lot for the station is located one block to the west. The station only uses the southern track for inbound and outbound trains. There is a station building that is no longer used and there are two small shelters. This station has limited weekday service and no weekend service. The station has been the western terminus of the line since 1983, although there have been proposals to once again have service to Phillipsburg, New Jersey.