New London County contains reservations of four of the five state-recognized Indian tribes, although the Paugassett were historically located farther west.

Connecticut's eight historical counties continue to exist in name only, and are no longer considered for statistical purposes.

[2] Southeastern New England was dominated by the Pequot people at the time of English colonization.

The "Homonoscet Plantation" was settled in March 1663, at first as Kenilworth, but was incorporated as the town of Killingworth in 1667.

[4] Several new towns were incorporated and added to New London over the next few decades: Preston in 1687, Colchester in 1699, and Lebanon in 1700.

The settlements along the Quinebaug Valley were placed in New London County in 1697, and incorporated as Plainfield in 1699.

By 1717, more towns were established in northeastern Connecticut and added to New London County between the Quinebaug Valley and the Rhode Island border.

Law enforcement within the geographic area of the county is provided by the respective town police departments.

Prior to 2000, a County Sheriff's Department existed for the purpose of executing judicial warrants, prisoner transport, and court security.

Several towns in New London County have organized the Southeastern Connecticut Regional Resources Recovery Authority.

Elementary only: There is also a privately endowed publicly funded school, Norwich Free Academy.

Since 1952, New London County has voted for the presidential candidate that won Connecticut.

In the last three presidential elections, Democratic strength was predominantly seen in the cities of New London and Norwich, as well as much of the county's southern and coastal areas.

As of the 2010 United States Census, there were 274,055 people, 107,057 households, and 69,862 families residing in the county.

[18] In terms of ancestry, 18.9% were Irish, 15.2% were Italian, 14.8% were English, 11.6% were German, 9.6% were Polish, and 3.7% were American.

[21] Data is from the 2010 United States Census and the 2006-2010 American Community Survey 5-Year Estimates.