Middlesex, Massachusetts

Middlesex County, Massachusetts
Middlesex South Registry of Deeds in Cambridge
Seal
Location in the U.S. state of Massachusetts
Massachusetts's location in the U.S.
Founded	May 10, 1643
Seat	Lowell and Cambridge
Largest city	Lowell
Area
• Total	847 sq mi (2,194 km2)
• Land	818 sq mi (2,119 km2)
• Water	29 sq mi (75 km2), 3.5%
Population
• (2010)	1,503,085
• Density	1,838/sq mi (710/km²)
Congressional districts	3rd, 4th, 5th, 6th, 7th
Time zone	Eastern: UTC-5/-4

Middlesex County is a county in the Commonwealth of Massachusetts, in the United States. As of 2016, the estimated population was 1,589,774, making it the twenty-first most populous county in the United States, and the most populous county in both Massachusetts and New England. For administrative purposes, the county holds two regions, Middlesex-North with its county seat in Lowell, and Middlesex-South with its county seat in Cambridge.

Middlesex County is included in the Boston–Cambridge–Newton, MA–NH Metropolitan Statistical Area.

The county government was abolished in 1997, but the county boundaries continue to describe a state district for court jurisdictions and for other administrative purposes, such as an indicator for elections. Massachusetts counties also define locations for National Weather Service weather alerts (such as severe thunderstorm warnings).

In 2010, the center of population of Massachusetts was located in Middlesex County, in the town of Natick.

The county was created by the Massachusetts General Court on May 10, 1643, when it was ordered that "the whole plantation within this jurisdiction be divided into four shires." Middlesex initially contained Charlestown, Cambridge, Watertown, Sudbury, Concord, Woburn, Medford, Wayland, and Reading. In the late 19th century and early 20th century, Boston annexed several adjacent cities and towns including Charlestown and Brighton from Middlesex County, resulting in an enlargement of Suffolk County. On April 19th, 1775, it became the site of the first armed conflict of the American Revolutionary War.