Dorothy McFadden Hoover (1918–2000)
Dorothy M. Hoover was a pioneer in the field of aeronautical mathematics and research. The granddaughter of slaves, she overcame the significant obstacles facing African-American women in the early part of the twentieth century to earn advanced degrees in physics and mathematics. One of her greatest achievements in aeronautical research was her contribution to the development of the “thin swept-back tapered wing,” which revolutionized flight. Her life story was essentially unknown until she was briefly mentioned in the highly acclaimed book Hidden Figures: The American Dream and the Untold Story of the Black Women Mathematicians Who Helped Win the Space Race (2016), by Margot Lee Shetterly. Hidden Figures, which was made into a major motion picture in 2016, told the story for the first time of black women mathematicians, or “computers,” who were key players in the space race.
Dorothy Estheryne McFadden was born in Hope (Hempstead County) on July 1, 1918, to William McFadden and Elizabeth Wilburn McFadden. She was the youngest of four children. She graduated from Henry C. Yerger High School in Hope in 1934 at the age of fifteen. McFadden arrived at Arkansas Agricultural, Mechanical, and Normal College (AM&N) (now the University of Arkansas at Pine Bluff) as a sixteen-year-old in 1934 and graduated in 1938 with a BS in mathematics, two months shy of her twentieth birthday. There were only two math majors in her class of 135 students. In the class of 1938 yearbook, The Lion, the quote associated with her picture was, “She handles big words as though she teethed on Webster’s dictionary.”
In a letter written to her mother, postmarked May 8, 1938, she requested that her mother try to arrange to come to graduation, since many of her classmates’ parents were coming. She also asked for “$6.50 which would cover the graduation fee that included $2.00 for a yearbook, $.55 for outstanding bookstore bill and $.09 each for 30 invitations.” She apologized for having to ask for money and mentioned she borrowed the $.03 stamp to send the letter.
For the years following graduation, she was a teacher. The 1940 U.S. census shows she was teaching school in rural Jesup, Georgia, earning $600 per year. In 1942, she married Sylvanus Bowe Clarke, who was inducted into the U.S. Army the following year during World War II. In 1943, Dorothy Clarke earned her master’s degree in mathematics from Atlanta University, a historically black college. Her thesis was titled, “Some Projective Transformation and Their Applications.”
As she was finishing her master’s program at Atlanta University, Langley Research Labs began hiring black female mathematicians as a result of President Franklin D. Roosevelt’s prohibition of racial discrimination in the national defense industry. Clarke was one of the first of six African-American women hired as mathematicians at Langley, with a pay of $2,000 per year. She worked at Langley from 1943 to 1953, during which time she achieved several firsts in the field of aeronautical research. Her graduate-level work helped set her apart from her peers, and she was exceptionally fluent in abstract mathematical concepts and complex equations. For that reason, her white female supervisor channeled to Clarke the rigorous mathematical assignments that came to the group from Langley engineer R. T. Jones’s Stability Analysis Division. In 1946, she was selected to work directly for Jones, arguably the preeminent aerodynamicist of the twentieth century. She thrived in the highly accomplished Stability Analysis Division.
In late 1946, Jones moved to California, and Clarke began working for his successor, Frank S. Malvestuto Jr., a brilliant engineer and prolific researcher. By 1951, she had earned the lofty title of Aeronautical Research Scientist, graded GS-9 in the government’s revamped rating system; the pay was nominally $5,400 per year. That same year, she was listed as co-author with Malvestuto on two significant research publications addressing “thin sweptback tapered wings” on aircraft. Being listed as a co-author was a landmark accomplishment, given that women, white or black, were not listed on research papers at the time—only white male engineers were.
Her contribution had real-world application in the development of America’s first jet fighter, the Sabre. It was the United States’ first swept-wing fighter jet that could counter the similarly winged Soviet MIG in the high-speed dogfights of the Korean War. Today, every plane that flies at supersonic speed utilizes delta or swept-back tapered wings, including commercial jets, fighter planes, and the space shuttle.
In 1947, Clarke had a daughter, Viola Clementine Clarke. Dorothy and Sylvanus divorced soon afterward, and in 1950, she married Richard Allen Hoover; they had a son, Ricardo Allen Hoover. Ricardo died in 1967 at age seventeen; Viola died in 1969 at age twenty-two. Dorothy and Richard also divorced.
In 1952, at what seemed the pinnacle of her career, Hoover took a four-year leave from the world of engineering to pursue her interests in theoretical mathematics. In 1954, she earned her second master’s degree, this one in physics at the University of Arkansas (UA) in Fayetteville (Washington County). A portion of her 1954 master’s thesis, “On Estimates of Error in Numerical Integration,” was included in the Proceedings of the Arkansas Academy of Science the following year. She is believed to be the first African-American woman to earn two technical master’s degrees. She also belonged to two physics and math honor societies.
In 1954, she accepted a John Hay Whitney Fellowship at the University of Michigan, where she undertook doctoral-level work in mathematics and physics. She left the University of Michigan in 1956, prior to completing her doctorate. Dorothy Hoover and her family returned to the Washington DC area, where she worked for three years at the U.S. Weather Bureau.
In 1959, she transferred to NASA’s Goddard Space Flight Center, where she was one of the few female mathematicians. While at Goddard, she continued the theoretical work she loved, continuing her publication record with a coauthored book on computational physics. After Vice President Lyndon B. Johnson released a report on minority employment in federal service, Hoover was promoted to GS grade 13, another first for a black woman, making about $11,000 per year.
After she retired, she wrote a book, A Layman Looks with Love at Her Church. This book was published in 1970 and charted the history of the African Methodist Episcopal Church. She became heavily involved with her church, the Campbell AME Church, located in the Anacostia DC area, and its outreach. She lived in Temple Hills, Maryland, a growing black middle-class community in southern Prince George’s County.
Hoover died on February 7, 2000, in Washington DC of complications from congestive heart failure.
For additional information:
Frazier, Lisa. “Searching for Dorothy.” Washington Post, May 7, 2000. Online at https://www.washingtonpost.com/archive/lifestyle/2000/05/07/searching-for-dorothy/b565fa48-6a5d-44c7-9267-453a33d492c6/?utm_term=.fc2a353317a7 (accessed June 29, 2018).
Hoover, Dorothy M. “Estimates of Error in Numerical Integration.” Proceedings of the Arkansas Academy of Science 8 (1955): 204–207. Online at https://scholarworks.uark.edu/jaas/vol8/iss1/23/ (accessed June 29, 2018).
Malvestuto, Frank S. Jr., and Dorothy M. Hoover. “Lift and Pitching Derivatives of Thin Sweptback Tapered Wings w/Stream Wise Tips and Subsonic Leading Edges at Supersonic Speeds.” National Advisory Committee for Aeronautics, Technical Note 2294. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930082953.pdf (accessed June 29, 2018).
———. “Supersonic Lift and Pitching Movement of Thin Sweptback Tapered Wings Produced by Constant Vertical Acceleration subsonic Leading Edges and Supersonic Trailing Edges.” National Advisory Committee for Aeronautics, Technical Note 2315. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930082993.pdf (accessed June 29, 2018).
Shetterly, Margot Lee. Hidden Figures: The American Dream and the Untold Story of the Black Women Mathematicians Who Helped Win the Space Race. New York: William Morrow, 2016.
Stewart, Shea. “Hope’s ‘Hidden Figure.’” Arkansas Democrat-Gazette, May 14, 2017, pp. 1E, 6E.
Richard D. Sallee
Oklahoma City, Oklahoma
Last Updated: 02/10/2020