Joseph P. Gerhardt was a German American restaurant and bar owner who became a colonel in the Union Army during the American Civil War. He was breveted a brigadier general in 1863 for gallantry in the field.

Prospect Hill Cemetery, also known as the German Cemetery, is a historic German-American cemetery founded in 1858 and located at 2201 North Capitol Street in Washington, D.C. From 1886 to 1895, the Prospect Hill Cemetery board of directors battled a rival organization which illegally attempted to take title to the grounds and sell a portion of them as building lots. From 1886 to 1898, the cemetery also engaged in a struggle against the District of Columbia and the United States Congress, which wanted construct a main road through the center of the cemetery. This led to the passage of an Act of Congress, the declaration of a federal law to be unconstitutional, the passage of a second Act of Congress, a second major court battle, and the declaration by the courts that the city's eminent domain procedures were unconstitutional. North Capitol Street was built, and the cemetery compensated fairly for its property.