Carlstadt was originally formed as a village by an Act of the New Jersey Legislature on March 12, 1860, within Lodi Township. The Borough of Carlstadt was incorporated on June 27, 1894, formally set off from Bergen Township, at the height of the Boroughitis phenomenon then sweeping through Bergen County.
According to the United States Census Bureau, the borough has a total area of 4.2 square miles (11.0 km²), of which, 4.0 square miles (10.2 km²) of it is land and 0.3 square miles (0.7 km²) of it (6.62%) is water.
Carlstadt is bordered on the south by East Rutherford in Bergen County, Secaucus and North Bergen in Hudson County, on the north by Wood-Ridge and Moonachie (Bergen) to the east by Ridgefield and South Hackensack (Bergen), and to the northwest by Wallington (Bergen). It is approximately 8 miles northwest of New York City and 95 miles northeast of Philadelphia.
There were 2,393 households out of which 25.7% had children under the age of 18 living with them, 51.9% were married couples living together, 10.8% had a female householder with no husband present, and 33.4% were non-families. 26.4% of all households were made up of individuals and 9.6% had someone living alone who was 65 years of age or older. The average household size was 2.47 and the average family size was 3.04.
In the borough the population was spread out with 19.0% under the age of 18, 7.7% from 18 to 24, 34.0% from 25 to 44, 24.0% from 45 to 64, and 15.3% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 94.1 males. For every 100 females age 18 and over, there were 92.4 males.
The median income for a household in the borough was $55,058, and the median income for a family was $62,040. Males had a median income of $46,540 versus $36,804 for females. The per capita income for the borough was $28,713. About 3.1% of families and 6.1% of the population were below the poverty line, including 7.8% of those under age 18 and 4.3% of those age 65 or over.
Carlstadt's Mayor is Will Roseman (R, term ends December 31, 2011). The Carlstadt Borough Council members are Council President Joe Crifasi (R, 2008), Richard E. Bartlett (R, 2010), Craig Lahullier (R, 2009), Dennis Ritchie (R, 2008), Dave Stoltz (R, 2010) and Bob Zimmermann (R, 2009).
In elections held on November 6, 2007, 48% of registered voters turned out to select a mayor and fill two seats on the borough council. Incumbent Republican William J. Roseman (1,153 votes) won reelection as mayor, defeating Democrat Thomas E. Dalton (469) and Independent candidate Frederick Stampone (15). Republican incumbent David A. Stoltz (998) and his running mate, newcomer Richard E. Bartlett (894), were elected to the council, defeating incumbent Democrat David B. Hollenbeck (718) and his running mate, Adrianna Cassiere Allen (603). The election sweep gives the Republicans control of all seats on the 2008 council.
On Election Day, November 7, 2006, Republican Party incumbents Robert J. Zimmerman (1,178 votes) and Craig J. Lahullier (1,170) swept the two open three-year seats on the Borough Council, defeating Democrats Adrianna Cassiere Allen (756) and Robert L. Cassella Jr. (739). The sweep retained the 5-1 Republican majority on the council. The voters passed a ballot question suggesting consideration of a minimum 75x100 foot lot size requirement for two-family homes by an 886-522 margin.
On the national level, Carlstadt is almost evenly split. In the 2004 presidential election, Republican George W. Bush received 50% of the vote here, edging Democrat John Kerry, who received around 49%.
For grades 9 to 12, public school students attend the Henry P. Becton Regional High School in East Rutherford, which serves high school students from both Carlstadt and East Rutherford. The school is part of the Carlstadt-East Rutherford Regional School District.