Hillsborough County, New Hampshire

Hillsborough was one of the five original counties identified for New Hampshire in 1769, and was named for Wills Hill, the Earl of Hillsborough who was British Secretary of State for the Colonies at the time. The county was organized at Amherst on March 19, 1771. In 1823 a number of towns were removed to become part of Merrimack County; the town of Merrimack remained in Hillsborough County, however. Over several years ending in 1869, county administrative functions were moved from Amherst first to Milford in 1866 then to the current seats of Manchester and Nashua.

According to the U.S. Census Bureau, the county has a total area of 892 square miles (2,310 km²), of which 876 square miles (2,270 km²) is land and 16 square miles (41 km²) (1.8%) is water.[3] The highest point in Hillsborough county is Pack Monadnock Mountain at 2,290 feet (700 m).

As of the 2010 United States Census, there were 400,721 people, 155,466 households, and 103,959 families residing in the county.[8] The population density was 457.4 inhabitants per square mile (176.6/km²). There were 166,053 housing units at an average density of 189.5 per square mile (73.2/km²).[9] The racial makeup of the county was 90.4% white, 3.2% Asian, 2.1% black or African American, 0.2% American Indian, 2.1% from other races, and 2.0% from two or more races. Those of Hispanic or Latino origin made up 5.3% of the population.[8]

Of the 155,466 households, 33.5% had children under the age of 18 living with them, 51.6% were married couples living together, 10.5% had a female householder with no husband present, 33.1% were non-families, and 25.3% of all households were made up of individuals. The average household size was 2.53 and the average family size was 3.05. The median age was 39.3 years.[8]

For the period 2011–2015, 24.8% of the county's population had French ancestry (including 9.9% of the total population with French Canadian ancestry), 20.9% had Irish, 13.1% had English, 10.2% had Italian, and 8.2% had German ancestry.[10] For the same time period, the estimated median annual income for a household in the county was $71,244, and the median income for a family was $85,966. Male full-time workers had a median income of $60,349 versus $44,270 for females. The per capita income for the county was $35,242. About 5.8% of families and 8.8% of the population were below the poverty line, including 11.7% of those under age 18 and 5.9% of those age 65 or over.[11]

Long the most populated county in New Hampshire, Hillsborough County has played a vital role in shaping the state's politics as a whole, although it has shifted in its own leanings over the years. Historically a Republican county going back to the 19th century, the county's more urban population made it receptive to Democrats in the early 20th century at a time when much of New England was solidly Republican. The county- and the state as a whole- voted Republican in every election since the founding of the Republican Party in 1856 until 1912, when both the county and the state were won by Democrat Woodrow Wilson. Four years later, Wilson's margin of victory in Hillsborough County enabled him to narrowly win the state as a whole despite losing the majority of counties, and making New Hampshire the only state to vote Democratic in New England and the entire Northeast in 1916.

In 1928, Hillsborough was the only county in New Hampshire to vote for Democrat Al Smith over Republican Herbert Hoover, and in the 1930s Franklin Roosevelt would solidify Democratic dominance there. In 1936, FDR would carry only 3 of New Hampshire's 10 counties, but his strong win in Hillsborough allowed him to narrowly win the state while neighboring Vermont and Maine were the only states in the nation to vote against him. In the 1940s, Roosevelt would take over 60% of the vote Hillsborough County, allowing him to win the state of New Hampshire by more comfortable margins in 1940 and 1944. The county would vote Democratic in every presidential election that followed until the 1970s, except for a win by Dwight D. Eisenhower in 1956, although it was still the only county in the state where Eisenhower failed to break 60% of the vote.

In the 1970s, shifting partisan allegiances and the growth of conservative Boston exurbs in southern New Hampshire caused a dramatic shift in Hillsborough County's politics, which also caused the state as a whole to become more conservative. Beginning in 1972, the county became reliably Republican in presidential elections, peaking in 1984, when Ronald Reagan would take over 70% of the vote there.

Although still one of the more Republican regions of the state, in the following years Democrats have made inroads and today it is an important swing county, correctly picking the winner of every presidential election since 1996. Both Republicans George H.W. Bush and George W. Bush would win it twice each, but Democrat Bill Clinton won it in 1996, and Barack Obama has won it twice in both 2008 and 2012, bolstering his wins of the state's electoral votes each time. In the 2012 presidential election, Time had listed Hillsborough as one of five critical counties affecting the outcome in the swing state of New Hampshire. Obama ended up winning with a margin of 50%-49%.[12] Although Donald Trump narrowly won the county in 2016, the county swung hard to the left in 2020, giving Joe Biden 53% of the vote, the highest percentage for any Democrat since 1964. The growth of the county due to its proximity to Massachusetts, and shift of college educated voters away from the Republican Party has further bolstered Democrats in Hillsborough County as of recently.

• National Register of Historic Places listings in Hillsborough County, New Hampshire

Wikimedia Commons has media related to Hillsborough County, New Hampshire.

• Hillsborough County web site
• National Register of Historic Places listing for Hillsborough County
• Hillsborough County Sheriff Office
• Historical material in Statistics and Gazetteer of New Hampshire (1875)