Don Alexander Hawkins, an architect by trade and mapmaker by passion whose historical detective work helped uncover the topography of Washington before its hills, marshes, forests and fields were tamed into the boulevards and monuments of the federal city, died Oct. 5 at his home in Hillsboro, Va. He was 86.
The cause was prostate cancer, said his wife, Cynthia Elliott.
Mr. Hawkins was once described by The Washington Post as a “dean” among the region’s residential architects. He designed or contributed to hundreds of projects across the city and the surrounding area — but was even better known for his discoveries of what Washington was like before any city existed there.
Largely self-taught in the rare specialty of historical cartography, Mr. Hawkins devoted decades to his study of the site that President George Washington chose for the capital, and the original plan for the city designed by the French-born architect Pierre Charles L’Enfant. In a demonstration of his fervor for history, Mr. Hawkins sometimes portrayed L’Enfant in costume.
By all accounts, Mr. Hawkins’s most significant work, a masterpiece of cartography, was a topographical map of Washington as it existed in 1791, when President Washington appointed L’Enfant to design the capital on the banks of the Potomac River.
Mr. Hawkins had yearned to know, a writer noted in a 2008 Post profile, precisely what L’Enfant saw “the rainy evening in March 1791” when he “rode alone into Georgetown with his pencils, compass and assorted drafting tools to begin the work of transforming 6,000 sparsely settled acres at the center of the new federal district into the capital of the freshly constituted United States.”
To produce the topographical study, which was described as the first of its kind, Mr. Hawkins referred to original maps, surveys, paintings, journals, letters and other archival clues. He finished the fifth draft of the map almost precisely 200 years after L’Enfant drew up his plan for the city. Mr. Hawkins’s work was published in the journal Washington History and is today housed at the Library of Congress.
“Its accuracy is incredible,” said Kenneth R. Bowling, the author of the book “The Creation of Washington D.C.: The Idea and Location of the American Capital,” describing the map as Mr. Hawkins’s “greatest contribution to Washington history.”
Among his insights, Mr. Hawkins offered evidence challenging the prevailing idea that Washington was built on a swamp. “For a riverside location, this city was unusually free of the kind of swampiness one should expect to find,” he said. “I calculated that only one percent of the L’Enfant Plan area was swampy.”
The impression of Washington as a swamp persists in popular culture, he said, because “‘swamp’ is a loaded word that is a handy metaphor for how people think of the political activity in Washington.”
Mr. Hawkins’s other historical undertakings included a map, a collaboration with his wife, displaying the original owners of the land that became the city of Washington; a reconstruction of the architect William Thornton’s original plan for the U.S. Capitol building; and a study of the interior of Federal Hall, the site in New York City, later demolished, where George Washington took the oath of office in 1789 and where the first Congress was convened.
“The loss to the D.C. historical community and to D.C. history itself is just incalculable,” Bowling said, referring to Mr. Hawkins’s death. “There was nobody like him.”
Donald Alexander Hawkins was born in Wheeling, W.Va., on April 24, 1937. He grew up in the Washington area, where both his parents worked as cryptanalysts, his mother for the CIA and its wartime predecessor, the Office of Strategic Services, and his father for the Army.
Mr. Hawkins recalled spending long hours of his childhood and adolescence — including many hours when he should have been in school — exploring Washington and the surrounding area. He was a graduate of Wakefield High School in Arlington, Va.
He studied at institutions including the Architectural Association in London and apprenticed with Hugh Newell Jacobsen, one of Washington’s most prominent architects, before opening an independent practice in 1969.
During graduate studies at Catholic University, where he received a master of architecture degree in urban design in 1977, Mr. Hawkins began his work on historical maps of Washington.
Mr. Hawkins was a past chairman of the Committee of 100 on the Federal City, a nonprofit urban planning organization. He was a regular contributor to Washington History and other publications and curated the exhibit “Washington: Symbol and City,” which opened in 2004 at the National Building Museum.
“In spite of the weaknesses of the city, of being essentially powerless in the face of Congress … we have shaped a unique city, a city with a great deal of vitality and variety,” he told the Capitol Hill publication Roll Call at the time.
Mr. Hawkins’s marriage to Ann Walczak ended in divorce. He and Elliott were married in 1996. Besides his wife, of Hillsboro, survivors include two children from his first marriage, Eli Hawkins of York, England, and Sarah Hawkins of Washington; and a granddaughter.
In recent years, Mr. Hawkins lived in Hillsboro in a 19th-century stone church that he and his family had renovated as a home. Last year, the roof suffered a fire that left the home inaccessible for months, and the extent of the damage, including the state of his map collection, remains unclear.
Mr. Hawkins kept most of his books and historical materials on the first floor and in the basement, his wife said, leading them to hope that not all was lost in the flames. He regarded his maps as living things, once describing them as “sentient.”