The county was named for Button Gwinnett, one of the delegates to have signed the United States Declaration of Independence on behalf of Georgia.
This county is a part of the Atlanta Metropolitan Area (Atlanta-Sandy Springs-Marietta, Georgia Metropolitan Statistical Area). It contains many suburbs of Atlanta, many of whose residents commute using Interstate 85. Despite recent efforts of forming a public bus system, the average commute time in Gwinnett County is 30.8 minutes, ranking it the highest in metro Atlanta and 18th highest nationwide (2003 census).
Gwinnett County's population is approximately 14 percent of the total Atlanta region population and has captured 26% of the region's growth since 2000, growing faster numerically than any other county in the region for the past 25 years running. It is the fourth-largest county on the list of 100 fastest-growing counties in the nation; for populous counties to have a high percentage growth rate is uncommon.
Gwinnett County Public Schools is the largest school system in Georgia and the fastest-growing in the Southeastern United States, with 113 total school facilities and a projected 2007—2008 enrollment of 159,258 students.
As of the census of 2000, there were 588,448 people, 202,317 households, and 152,344 families residing in the county. The population density was 1,360 people per square mile (525/km²). There were 209,682 housing units at an average density of 485 per square mile (187/km²). The racial makeup of the county is currently 52.2% White non-Hispanic, 19.8% Black, 0.2% Native American, 9.1% Asian, 0.1% Pacific Islander, 4.32% from other races, and 2.15% from two or more races. 17.1% of the population were Hispanic or Latino of any race. Gwinnett County has the largest Latino and Asian populations in the state of Georgia.
There were 202,317 households out of which 42.30% had children under the age of 18 living with them, 61.20% were married couples living together, 10.00% had a female householder with no husband present, and 24.70% were non-families. 18.40% of all households were made up of individuals and 3.10% had someone living alone who was 65 years of age or older. The average household size was 2.88 and the average family size was 3.28.
In the county the population was spread out with 28.20% under the age of 18, 8.70% from 18 to 24, 37.50% from 25 to 44, 20.30% from 45 to 64, and 5.40% who were 65 years of age or older. The median age was 32 years. For every 100 females there were 101.70 males. For every 100 females age 18 and over, there were 100.10 males.
The median income for a household in the county was $60,537, and the median income for a family was $66,693. Males had a median income of $42,343 versus $31,772 for females. The per capita income for the county was $25,006. About 3.80% of families and 5.70% of the population were below the poverty line, including 5.90% of those under age 18 and 5.50% of those age 65 or over.
Gwinnett County is accessible by major interstates as well as several US Highways. Interstate 85 runs through Gwinnett from DeKalb County at its southwestern entry point, and Barrow County in the northeast. Interstate 985 branches off Interstate 85 at Exit 113 near Suwanee.
Several U.S. Highways run through Gwinnett County as well. US Route 23 runs through Duluth and Suwanee. US Route 29 runs through Central Gwinnett through Lawrenceville. US Route 78 runs through the Southern portion of Gwinnett County. All of the U.S. Highways are east-west throughout Gwinnett County (although U.S. Routes 23 and 29 run north-south throughout most of its route).
Gwinnett County is served by several Georgia State Routes. State Route 316 branches off Interstate 85 at Exit 106 after the Pleasant Hill Exit 104. This highway connects metropolitan Atlanta with Athens, where the University of Georgia is located. A second route is State Route 124, also known as Scenic Highway. This serves as the main route between Lawrenceville and Snellville. A third highly used route is State Route 120, which runs from Tallapoosa (west of Atlanta) to Lawrenceville. A fourth major route is State Route 20, which runs Northwest to Southeast in Gwinnett County through Grayson, Lawrenceville, Buford, Sugar Hill, and Cumming (in Forsyth County). And a fifth major route is State Route 8, which parallels State Route 316, connects East to West between Auburn, Dacula, Lawrenceville (where it merges with US Route 29) and continues through Lilburn and eventually into Atlanta and Austell.
Gwinnett County is primarily reached through Atlanta Hartsfield-Jackson International Airport. The county also has its own airport, the Gwinnett County Briscoe Field. This is Gwinnett's municipal airport near Lawrenceville, accessible by GA Route 316.
Gwinnett also operates its own public transportation. The Gwinnett County Transit (GCT), formed in 2000 and starting local service in 2002, serves much of central and north Gwinnett, and provides easy access to the Doraville MARTA station in northeastern DeKalb County, as well as transportation between major commercial and residential areas.
At present, Gwinnett County is not connected to the Atlanta Area's MARTA rail system. Several proposals have been made regarding rail transit that would pass through Gwinnett, most recently a "university link" system that would link Georgia State University in Atlanta, Georgia Institute of Technology in Atlanta and the University of Georgia in Athens. Potential stops within Gwinnett County include Lilburn, Lawrenceville and Dacula, among other possibilities.