[2] Hartford County is included in the Hartford-East Hartford-Middletown metropolitan statistical area.

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

The "Thirty Miles Island" referred to in the constituting Act was incorporated as the town of Haddam in 1668.

[5] In 1670, the town of Simsbury was established, extending Hartford County to the Massachusetts border.

In 1714, all of the unincorporated territory north of the towns of Coventry and Windham in northeastern Connecticut to the Massachusetts border were placed under the jurisdiction of Hartford County.

In the late 18th and early 19th centuries, the establishment of several more towns resulted in minor adjustments in the bounds of the county.

The final adjustment resulting in the modern limits occurred on May 8, 1806, when the town of Canton was established.

The surface is very diverse: part of the river valleys are alluvial and subject to flooding, while other portions of the county are hilly and even mountainous.

[8] In Connecticut, there is no county-level executive or legislative government; the counties determine probate, civil and criminal court boundaries, but little else.

In Connecticut, cities and towns may agree to jointly provide services or establish a regional school system.

As of the 2010 United States census, there were 894,014 people, 350,854 households, and 227,831 families living in the county.

Since then, it has become solidly Democratic similar to most of New England, with the only Republicans to carry the county since then being Richard Nixon and Ronald Reagan in their 49-state landslide victories of 1972 and 1984, respectively.