The village is known as "The Gem of the Fox River Valley", since its downtown is nestled in the heart of Illinois' Fox River Valley. Established in 1890 and long known as a small river community, the village is currently making the transition into a major regional hub, as it has experienced considerable suburban growth over the past 15 years. Now stretching all the way west to the busy Randall Road corridor, Algonquin has become a major center of retail activity and a growing business center. Additionally, the village continues to see considerable residential growth. In wake of the growth, the village has had to deal with challenges such as traffic congestion and overburdened schools. In spite of this, the Village has managed to grow its commercial tax base, preserve its character and history, and substantially increase its recreational offerings.
As of the census of 2004, there were 27,900 people, 8,300 households, and 7,100 families residing in the village. The population density was 2,367.4 people per square mile (914.2/km²). There were 7,952 housing units at an average density of 808.8/sq mi (312.3/km²). The racial makeup of the village was 94.26% White, 0.92% African American, 0.10% Native American, 2.35% Asian, 0.01% Pacific Islander, 1.20% from other races, and 1.16% from two or more races. Hispanic or Latino of any race were 4.07% of the population. Within the last decade, the Polish Community has doubled.
There were 8,000 households out of which 50% had children under the age of 18 living with them, 74.7% were married couples living together, 5.6% had a female householder with no husband present, and 17.8% were non-families. 14.5% of all households were made up of individuals and 3.5% had someone living alone who was 65 years of age or older. The average household size was 3.02 and the average family size was 3.38.
In the village the population was spread out with 32.8% under the age of 18, 5.2% from 18 to 24, 36.8% from 25 to 44, 20.0% from 45 to 64, and 5.3% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 98.9 males. For every 100 females age 18 and over, there were 96.2 males.
The median income for a household in the village was $79,730, and the median income for a family was $84,437 (these figures had risen to $90,073 and $102,766 respectively as of a 2007 estimate). Males had a median income of $60,473 versus $36,624 for females. The per capita income for the village was $29,820. About 1.0% of families and 1.7% of the population were below the poverty line, including 1.5% of those under age 18 and 4.6% of those age 65 or over.
Algonquin is a center of transportation for McHenry and Kane Counties. Some of the major roadways include: