Question: Where was the university at which Donald N. Langenberg  served on the Board of Trustees at the located? 
Sentence (from "University of the District of Columbia"): The University of the District of Columbia (UDC) is the only public university in the U.S. capital of Washington, D.C. UDC is one of the few urban land-grant universities in the country and a member school of the Thurgood Marshall College Fund.
Relevant evidence: Yes