Dennis Horn, 74, devoted husband and father, beloved by family and friends, passed away peacefully at home on December 13, 2024, surrounded by his wife of 42 years Diane and sons Jonathan and David. He was the loving grandfather of Jordan and Leo Horn. Dennis embraced life to the fullest. He cherished his family and friends and nurtured his relationships in ongoing and significant ways, with a generous and caring spirit.  He was a smart, conscientious and widely respected real estate and business attorney. Over 47 years in practice as a real estate attorney, Dennis led legal work for numerous projects significant to the revitalization of Washington. He was widely admired by his clients and colleagues. Dennis was warm and witty, and a voracious reader. His intellectual curiosity and determination to have a full and productive life following his retirement led him to enter graduate school and receive a M.A. in history in 2024.

Dennis was born on April 10, 1950, in Elmira, New York, to Joyce and Irving Horn. He grew up in Elmira, where his mother was a homemaker, and his father was a dentist.  Dennis graduated from Elmira Free Academy in 1968, where his academic achievements included membership in the National Honors Society and winning a National Merit Scholarship. He was also on the high school debate team, ran cross country, and was on the wrestling team, winning Outstanding Wrestler awards. Dennis was an Eagle Scout, and in the Jewish community was a member of AZA. 

Dennis continued his education at the University of Rochester, where he graduated with a B.A. with highest honors in history and economics in 1972.  He received a Rotary scholarship to study at the London School of Economics and Political Science, where he was awarded an M.S. in Urban and Regional Planning, and then to the University of Pennsylvania Law School, from which he received a J.D.

Dennis loved to travel with his family and made frequent trips in the United States, to Europe and to Japan. He particularly enjoyed their trips to Aspen, CO in the summer for Music School concerts and intellectual events.  He loved the outdoors, enjoying hiking, biking, camping and fly fishing.   He was an avid reader, with over 15 different library cards.   A lifelong learner, he constantly was exploring new ideas and concepts, be they history, economics, or anything that he hadn’t tried yet. Like his father, Irving Horn, Dennis had a keen interest in other people, and liked to greet those around him in parks, in his neighborhood, and anywhere he went.   He loved watching movies and television shows with his family, and also had a deep love for the theatre.

Dennis was a partner at the firm of Holland & Knight. He lectured and wrote extensively about various aspects of commercial real estate development. He served as a member of the District of Columbia Mayor's Terrorism Task Force, assisting the Mayor with the city's response to the commercial and business impact of the September 11, 2001 terrorist attacks. Over his 47 years as a practicing real estate attorney, Dennis led legal work for landmark developments in Washington, among them: Amtrak’s $1.1 high speed rail project, development of over 800,000 square feet in Georgetown and in the West End, and the Research and Innovation Campus of Children’s National Hospital. In addition, Dennis led a team of lawyers and other professionals representing a private real estate fund in the acquisition, development and dispositions of over $1.2 billion of real estate nationwide.  He was designated as a Super Lawyer from 2007-2020. Dennis provided pro bono counsel to several non-profits including the Friends of the Library Montgomery County.

In the late 1990s, Dennis headed a task force that recommended a program for regulatory reform in the District of Columbia which was largely implemented by the D.C.

Council.  That experience inspired Dennis’s Master’s Thesis at UMD later in 2024, entitled “The Clash between Race and Politics: Marion Barry, the District of Columbia Financial Control Board, and the Fight for Home Rule.”

Before joining Holland & Knight, Mr. Horn was a partner in the law firm of Dunnells & Duvall, which merged with Holland & Knight in January 1994. He previously served as General Counsel to Levitt Homes, Incorporated in Boca Raton, Florida, and was associated with the law firm of Fried Frank, Harris, Shriver & Jacobson of Washington, D.C. In 2004, Dennis edited a book entitled The Commercial Lease Book – Expert Tools for Drafting and Negotiation (ABA Publishing 2004) which has become an ABA Real Property, Probate and Trust Law Section best seller.

Dennis

In addition to his wife and sons, Dennis is survived by his sisters Linda Horn Schatz and Sherry Horn Keller, daughter in law, Adi Horn, and grandsons Jordan Horn and Leo Horn.

Funeral services will be held on Wednesday, December 18, 2024, 11:30am, Bethesda Jewish Congregation with interment to follow at Garden of Remembrance Memorial Park. Memorial contributions can be made to the Friends of the Library, Pancreatic Cancer Action Network, or a charity of your choice.