Hillsborough Township is a township in Somerset County, New Jersey, United States. As of the 2010 United States Census, the township's population was 38,303, reflecting an increase of 1,669 (+4.6%) from the 36,634 counted in the 2000 Census.
Hillsborough Township was originally created by Royal Charter on September 12, 1771, from portions of Western precinct. It was incorporated by an act of the New Jersey Legislature on February 21, 1798, as one of New Jersey's original group of 104 townships. Portions of the township were taken to form the boroughs of Millstone (May 14, 1894) and Manville (April 1, 1929). The township's name may have come from an earlier name of "Hillsbury", though it may have been named for Wills Hill, 1st Marquess of Downshire who was the Earl of Hillsborough.
Hillsborough Township quickly took its place in history as the path General George Washington and his troops traveled from the Battle of Princeton to winter quarters in Morristown. While the British were encamped in the valley below awaiting an opportunity to attack, it is said that Washington drilled his troops on the Sourland Mountain around a spring near the top using different formations and corn stalks for guns. As the sun caught the stalks, the British thought Washington had received reinforcements and fresh supplies. The British troops, thinking that they were outnumbered, slipped off to New Brunswick leaving Washington to continue to Morristown.
The township was formally incorporated on February 21, 1798.
Hillsborough is the home of the Belle Mead GSA depot, or Belle Mead General Depot, which was a storage site for materials during World War II, along with housing Italian and German prisoners of war. It continued storing materials until the 1980s, and various contaminants have leaked into the ground and surrounding area during that time. Efforts are under way to convert the site into a mixed recreation and R&D complex.
Hillsborough is home to Duke Farms, a 2,700 acres estate in the north-eastern quadrant of the town that was originally owned by tobacco and electric energy tycoon James "Buck" Duke and then passed down to daughter Doris Duke, and is now one of the few remaining "preserved" natural areas in Hillsborough Township.
In Money magazine's 2013 Best Places to Live rankings, Hillsborough was ranked 16th in the nation, the third-highest among the three places in New Jersey included in the top 50 list. In the magazine's 2007 rankings, the township was ranked as the 23rd best place to live in the nation.
According to the United States Census Bureau, the township had a total area of 55.001 square miles (142.453 km2), including 54.536 square miles (141.248 km2) of land and 0.465 square miles (1.204 km2) of water (0.85%).
Unincorporated communities, localities and place names located partially or completely within the township include Amwell, Belle Mead, Blackwells Mills, Champlain,Cloverhill, Clover Mill, Flagtown, Frankfort, Hamilton, Higgins Mills, Montgomery, Neshanic, Pleasant View, Royce Field, Royce Valley, South Branch, Woods Tavern and Zion.
The township borders Branchburg Township, Bridgewater Township, Franklin Township, Manville, Millstone, Montgomery Township, Raritan and Somerville in Somerset County; and East Amwell Township, Raritan Township and Readington Township in Hunterdon County.