Duncanson Avenue, currently known as Seminole Street, was named after Charles C. “Chas” or “C.C.” Duncanson (circa 1846–1920). He was a lifelong resident of the District of Columbia and one of the six founders who formed the Charlton Heights Improvement Company (CHIC) on August 29, 1888. CHIC built more than two dozen homes in the area now known as Berwyn Heights.

Duncanson was a Mason, as well as, a prominent real estate agent and owner of the Duncanson Brothers auctioneering company. In 1885, he was an active participant on a committee that planned and organized events for President-Elect Grover Cleveland’s inauguration. He was also a member of a committee to celebrate the one hundredth anniversary of the laying of the cornerstone of the Capitol of the United States. His wife, Eliza H. (circa 1850-1924), initiated lunacy proceedings against him in 1903, whereby he was adjudged insane. For the next seventeen years, Duncanson was a regular resident of several hospitals including St. Elizabeth’s Government Hospital where he died on March 27, 1920.

Explanation of Language:
Until the early 21^st century, “lunacy” was the legal term to describe mental disorders or illness and was used for legislative acts and legal proceedings. The judicial process was known as a lunacy proceeding and was used to commit a person to an asylum or mental hospital. The 21st Century Language Act of 2012 removed the word “lunacy” from federal legal proceedings.