Question: Where was the university at which Donald N. Langenberg  served on the Board of Trustees at the located? 

Context paragraphs:
Bernos: Bernos (also transliterated Barnos, Burnos) is a wool cloak-like garment and hood woven in one piece, worn by Ethiopian highlanders.  The term seems to be an adaptation of the Arab version of Burnous.  Donald N. Levine notes that the wealthier men of Menz "wear the "barnos", a tailored cape made of dark wool."

Donald N. Sills: Dr. Donald N. Sills was a Baptist minister and one of the founders of George Wythe College, and previous chairman of the George Wythe Foundation Board of Trustees.  He served as the first president of George Wythe College (now known as George Wythe University), and was succeeded by Oliver DeMille.

Cornell University Board of Trustees: The Cornell University Board of Trustees is the board of trustees for Cornell University, a private, Ivy League university located in Ithaca, New York.  The board is vested with "supreme control" over the entire university, in accordance to university bylaws.  The board's major responsibilities are to establish the degrees that are awarded by the university, elect the president, and adopt an annual plan of financial operation.  Day-to-day administration has been delegated by the trustees to the president.  There are 64 voting members on the board, including students, employees, faculty, and alumni that are voted onto the board by their respective group.  The four ex officio members of the board are the president of the university, the governor of the state of New York, the speaker of the state assembly, and the president of the state senate.  The current chairman of the board is Robert Harrison.

Deirdre McCloskey: Deirdre Nansen McCloskey (born September 11, 1942), formerly known as Donald N. McCloskey, is the Distinguished Professor of Economics, History, English, and Communication at the University of Illinois at Chicago (UIC).  She is also adjunct professor of Philosophy and Classics there, and for five years was a visiting Professor of philosophy at Erasmus University, Rotterdam.  Since October 2007 she has received six honorary doctorates.  In 2013, she received the Julian L. Simon Memorial Award from the Competitive Enterprise Institute for her work examining factors in history that led to advancement in human achievement and prosperity.  Her main research interests include the origins of the modern world, the misuse of statistical significance in economics and other sciences, and the study of capitalism, among many others.

Donald N. Bastian: Donald N. Bastian is a retired Bishop of The Free Methodist Church of North America, serving in this office from 1974-1990.  In 1990 he was elected the first bishop of the newly formed Free Methodist Church in Canada, from which office he retired in 1993.  He and his wife, Kathleen, live in Brampton, Ontario.

Peterson Ridge: Peterson Ridge ( ) is a high rock ridge that extends north from the west part of Storm Peak massif, in Queen Alexandra Range.  Named by the Ohio State University Geological Expedition, 1969–70, for Donald N. Peterson, party member who collected basalt lavas from the ridge for petrologic and paleomagnetic studies.

Donald N. Langenberg: Donald Newton Langenberg (born March 17, 1932) is a physicist and college professor.  He formerly served as chancellor of the University System of Maryland and the University of Illinois, Chicago.  Langenberg has taught at the University of Oxford, the École Normale Supérieure, the California Institute of Technology, and the Technische Universität München and has served on the Board of Trustees at the University of the District of Columbia and the University of Pennsylvania.

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.

Simple Rules: How to Thrive in a Complex World: Simple Rules: How to Thrive in a Complex World is a 2015 business strategy book co-authored by Donald N. Sull, a Senior Lecturer at the MIT Sloan School of Management, and Kathleen M. Eisenhardt, a Professor at the Stanford University School of Engineering.

The Killam Trusts: The Killam Trusts were established in 1965 after the death of Mrs. Dorothy J. Killam, the widow of Izaak Walton Killam, a Canadian financier, for a time the wealthiest man in Canada.  He died intestate in 1955, but before his death he and his wife discussed in extensive detail the scholarship plan on which the Killam Trusts were founded.  Approximately one half of his estate went to the government as inheritance tax.  It was used to found the Canada Council, along with similar funds from the estate of Sir James Dunn, also from Nova Scotia).  The rest of Mr. Killam's estate was inherited by his widow, Dorothy J. Killam.  In the ten years between his death and hers, she doubled the Killam fortune.  Upon her death at Villa Leopolda, her estate in France, her lawyer Donald N. Byers, QC put into motion the plans the Killams had discussed during their lifetimes.  Having no children of their own, the Killams decided to leave their fortune to further post-secondary education in Canada at the graduate studies level.

Supporting paragraphs: Donald N. Langenberg University of the District of Columbia
Answer: Washington, D.C.