The Town of Rotterdam is in the south-central part of the county. It was founded in the 1820s by Dutch settlers, who named it after the port of Rotterdam in the Netherlands, where many emigrants last touched European grounds. The town borders the City of Schenectady. Rotterdam is the headquarters of Price Chopper, a supermarket chain in Upstate New York and New England.
As of the census of 2000, there were 28,316 people, 11,544 households, and 8,092 families residing in the town. The population density was 787.0 people per square mile (303.9/km²). There were 11,990 housing units at an average density of 333.3/sq mi (128.7/km²). The racial makeup of the town was 97.26% White, 0.95% Black or African American, 0.16% Native American, 0.57% Asian, 0.01% Pacific Islander, 0.21% from other races, and 0.83% from two or more races. Hispanic or Latino of any race were 0.97% of the population.
There were 11,544 households out of which 29.4% had children under the age of 18 living with them, 55.7% were married couples living together, 10.6% had a female householder with no husband present, and 29.9% were non-families. 25.8% of all households were made up of individuals and 12.6% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 2.94.
In the town the population was spread out with 23.1% under the age of 18, 5.8% from 18 to 24, 27.9% from 25 to 44, 24.1% from 45 to 64, and 19.1% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 92.9 males. For every 100 females age 18 and over, there were 88.5 males.
The median income for a household in the town was $46,267, and the median income for a family was $54,542. Males had a median income of $37,536 versus $27,527 for females. The per capita income for the town was $21,457. About 2.8% of families and 4.5% of the population were below the poverty line, including 5.2% of those under age 18 and 5.9% of those age 65 or over.