Harford County, Maryland

Harford County is a county located in the U.S. state of Maryland. As of the 2020 census, the population was 260,924. Its county seat is Bel Air. Harford County is part of the Baltimore metropolitan area and the Washington–Baltimore combined statistical area. The county is part of the Central Maryland region of the state.

In 1608 the area was inhabited by Massawomecks and Susquehannocks. The first European to see the area was John Smith in 1608 when he traveled up the Chesapeake Bay from Jamestown. In 1652, the English and Susquehannocks signed a treaty at what is now Annapolis for the area now called Harford County.

Harford County was formed on March 22, 1774, from the eastern part of Baltimore County with a population of 13,000 people. On March 22, 1775, Harford County hosted the signers of the Bush Declaration, a precursor document to the American Revolution. On January 22, 1782, Bel Air became the county seat.

Havre de Grace, a city incorporated in 1785 within Harford County, was once under consideration to be the capital of the United States rather than Washington, D.C. It was favored for its strategic location at the top of the Chesapeake Bay; this location would facilitate trade while being secure in time of war. Today, the waterways around Havre de Grace have become adversely affected by silt runoff, which is one of the primary environmental issues of Harford County. While today the site is a Maryland National Guard military reservation, the land was used as the Havre de Grace Racetrack where racehorse Man o' War ran in 1919 and 1920.

During the 1900s the Bata Shoe Company employed numerous Eastern European refugees at the Belcamp factory. In the 1940s the Susquehanna River tributary Broad Creek was dammed to form the 55 acres (0.22 km²) at what is now the Broad Creek Memorial Scout Reservation. In June 1972 Hurricane Agnes overflowed the dam and flooded areas in many states. On the County Health Rankings & Roadmaps by the Robert Wood Johnson Foundation with the University of Wisconsin Population Health Institute, "prior to the 2016 report ... Harford's yearly rankings typically fell between ninth and 10th place, primarily because of the percentage of county residents who were obese or who smoked." Scenes from Tuck Everlasting, From Within, and House of Cards were all filmed in Harford County.^{[citation needed]}

In 2011 the Office of National Drug Control Policy deemed Harford County a designated High Intensity Drug Trafficking Area.

The county was named for Henry Harford (c. 1759–1834), the illegitimate son of Frederick Calvert, 6th Baron Baltimore. Henry Harford was born to Calvert's mistress, Hester Whelan, whose residence still stands as part of a private residence on Jarretsville Pike, in Phoenix, Maryland. Harford served as the last Proprietary Governor of Maryland but, because of his illegitimacy, did not inherit his father's title. There are 79 properties and districts listed on the National Register in the county, including one National Historic Landmark called Sion Hill.

Harford County has environmental issues in three major areas: land use, water pollution/urban runoff, and soil contamination/groundwater contamination.