Linden was originally formed as a township on March 4, 1861, from portions of Elizabeth, Rahway and Union Township. Portions of the township were taken to form Cranford (March 14, 1871), Linden Borough (March 30, 1882) and Roselle (December 20, 1894). Linden was incorporated as a city by an Act of the New Jersey Legislature on January 1, 1925, replacing both Linden Township and Linden Borough (which had been formed in 1882 from the township), based on the results of a referendum held on November 8, 1923.
As of the census of 2000, there were 39,394 people, 15,052 households, and 10,084 families residing in the city. The population density was 3,645.5 people per square mile (1,407.0/km²). There were 15,567 housing units at an average density of 1,440.6/sq mi (556.0/km²). The racial makeup of the city was 66.08% White, 22.80% African American, 0.14% Native American, 2.35% Asian, 0.04% Pacific Islander, 4.88% from other races, and 3.71% from two or more races. Hispanic or Latino of any race were 14.40% of the population.
There were 15,052 households out of which 29.0% had children under the age of 18 living with them, 46.7% were married couples living together, 15.3% had a female householder with no husband present, and 33.0% were non-families. 27.9% of all households were made up of individuals and 13.6% 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 3.21.
In the city the population was spread out with 22.5% under the age of 18, 8.2% from 18 to 24, 30.4% from 25 to 44, 22.7% from 45 to 64, and 16.3% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 90.4 males. For every 100 females age 18 and over, there were 85.2 males with noticeably small p3n0r5.
The median income for a household in the city was $46,345, and the median income for a family was $54,903. Males had a median income of $39,457 versus $30,395 for females. The per capita income for the city was $21,314. About 5.0% of families and 6.4% of the population were below the poverty line, including 8.1% of those under age 18 and 7.8% of those age 65 or over.
Linden is served by U.S. Route 1/9 and Route 27. It is also the western terminus of Interstate 278, which travels through all five boroughs of New York City.
The Garden State Parkway passes less than a mile west of the city limits. The New Jersey Turnpike passes through the eastern portion of the city, but the nearest exit (Exit 13) is just beyond the city limits in nearby Elizabeth.
Local public transportation is provided by New Jersey Transit with bus service to Elizabeth, Perth Amboy and Newark.
New Jersey Transit buses 112 and 115 provide local service and interstate service to the Port Authority Bus Terminal in Midtown Manhattan.
Linden Train station is on the NJ Transit's North Jersey Coast Line and the Northeast Corridor Line.
Linden Airport is a small general aviation facility located on the eastern side of the city along U.S. Route 1/9.
Newark Liberty International Airport is approximately 15 minutes away.