Biohazard Cleanup Near Adelphi Park Adelphi, MD

Adelphi is an unincorporated community and census-designated place in Prince George's County, Maryland, located just northeast of Washington, D.C.

The community takes its name from the historic Adelphi Mill, established in 1796 along the Northwest Branch of the Anacostia River, which still stands today and can be rented for special events.

The 2020 census counted 16,823 residents in Adelphi, an increase of 11.5 percent from the 15,086 residents counted in 2010.

The 2020 census counted 5,266 households and 5,598 housing units in Adelphi.

Adelphi is a young, densely settled suburb, with a median age of 32.9 years in 2020 and about 6,194 residents per square mile across its roughly 2.7 square miles.

Hispanic or Latino residents made up just over half of Adelphi's population in the 2020 census, reflecting the community's large immigrant population near neighboring Langley Park.

Adelphi is served by ZIP codes 20783 and 20787.

In the 19th century, banker George Washington Riggs acquired much of the area as his Green Hill estate, and part of it later became Leander McCormick-Goodhart's Langley Park estate.

Labor organizer Mary Harris "Mother" Jones died in 1930 at the farm of Walter and Lillie May Burgess near Powder Mill and Riggs Roads in present-day Adelphi.

Unlike nearby Hyattsville and College Park, Adelphi stayed relatively undeveloped until after World War II, when subdivisions quickly filled in and banded together in the mid-1950s under the Adelphi name to honor the old mill.