Gwendolyn Midlo Hall (born 27 June 1929) is an American historian who focuses on the history of slavery in the Caribbean, Latin America, Louisiana (United States), Africa, and the African Diaspora in the Americas. Discovering extensive French and Spanish colonial documents related to the slave trade in Louisiana, she wrote Africans in Colonial Louisiana: The Development of Afro-Creole Culture in the Eighteenth Century (1992), studied the ethnic origins of enslaved Africans brought to Louisiana, as well as the process of creolization which created new cultures. She changed the way in which several related disciplines are researched and taught, adding to scholarly understanding of the diverse origins of cultures throughout the Americas.
In addition, Midlo Hall created a database of records identifying and describing more than 100,000 enslaved Africans. It has become a primary resource for historical and genealogical research. She earned recognition in academia, and has been featured in the New York Times, People Magazine, ABC News, BBC, and other popular outlets for her contributions to scholarship, genealogy, and the critical reevaluation of the history of slavery. 
Midlo Hall is an award-winning author and Professor Emerita of Latin American and Caribbean History, Rutgers University, New Jersey. Since 2010 she is Professor of History at Michigan State University.
Gwendolyn Midlo was born June 27, 1929 in New Orleans, Louisiana, the daughter of Ethel and Herman L. Midlo, a civil rights and labor attorney. Her parents were of Russian- and Polish-Jewish ancestry. She was influenced by her father's activism.   In 1990 her mother founded the Ethel and Herman Midlo Center for New Orleans Studies at the University of New Orleans, where her father had donated his papers. 
Midlo has had a career marked by early political activism as well as academic scholarship. After World War II, at age 16 in 1945, Hall helped organize and participated in the New Orleans Youth Council, an interracial, direct-action community group, which encouraged and helped African-American voter registration and defied racial segregation laws. In 1946 she was elected to the Executive Board of the Southern Negro Youth Congress at the Southern Youth Legislature in Columbia, South Carolina. It had operated since 1937 to end lynching, racial discrimination and segregation, and to achieve voting rights for all. 
Midlo helped organize Young Progressives, an interracial youth and student movement in segregated New Orleans that included students from Tulane University, Newcomb College, and Loyola University (white colleges) and from Dillard and Xavier universities ( historically black colleges.) She was active in the 1948 presidential campaign of Henry Wallace, the Progressive Party candidate, working in New Orleans, rural Louisiana, and Atlanta, Georgia. She also was active in the Civil Rights Congress and the Southern Conference for Human Welfare. 
Starting at Sophie Newcomb College of Tulane University, Midlo studied history. After years of political activism and marriage, Midlo Hall completed some of her academic studies outside the United States, which gave her broader insight as she acquired fluency in French and Spanish and could use archives in other countries. She earned a B.A. in history at Mexico City College, 1962 and a master's in Latin American History, also at Mexico City College in 1963-64.
While a doctoral graduate student at the University of Michigan, Midlo Hall published an article advocating medical treatment for heroin addicts: "Mechanisms for Exploiting the Black Community", The Negro Digest, November 1969. It inspired demonstrations in the streets of Detroit. She organized methadone-maintenance treatment programs in both Detroit and Ann Arbor, Michigan. Adoption of such treatment by major cities helped reduce heroin use and the crime rate in the inner city of Detroit and others.  Midlo Hall earned a Ph.D. in Latin American History at the University of Michigan, Ann Arbor, in 1970.
Midlo Hall and Haywood moved to Mexico City, Mexico, in early 1959, shortly before he was expelled from the Communist Party over ideological differences. Midlo Hall completed her B.A. and master's degrees in Mexico City before returning to the US in 1964. In 1966 she started her graduate studies to earn her doctorate at the University of Michigan. The couple separated and she raised their children by herself after 1964.
In 1965, while teaching black students at Elizabeth City State College in North Carolina, Midlo Hall encouraged them to organize armed resistance against the Ku Klux Klan and to oppose the United States military intervention in Vietnam.  She chaired the Defense Committee for civil rights leader  Robert F. Williams when he was extradited from Michigan to Monroe, North Carolina in 1975.  During the 1960s and early 1970s, she published a number of influential essays in African-American magazines. Midlo Hall was fired and blacklisted in 1965 by Elizabeth City State College and the F.B.I. for her activities. 
When she moved to Michigan, Midlo Hall worked in Detroit during 1965 and 1966, often with Grace Lee Boggs, as a temporary legal secretary. She had to keep a step ahead of the F.B.I. which tried to get her fired from wherever she worked.  The F.B.I. engineered the eviction of Midlo Hall and her two young children from three apartments which she rented in Michigan during her first year: two in Detroit and one in Ann Arbor.  She persisted in completing course work and her Ph.D. dissertation for her doctorate, which was published as Social Control in Slave Plantation Societies: A Comparison of St. Domingue and Cuba (1971) by Johns Hopkins University Press.
After completing her doctorate, Midlo Hall started as an assistant professor at Rutgers University in New Brunswick, New Jersey, where she advanced to full professor in 1993. She taught Caribbean and Latin American history, as well as classes on the African diaspora. Publication in 1992 of her Africans in Colonial Louisiana supported a reevaluation of African-American contributions to Louisiana and United States culture. She discovered significant colonial data in courthouses in Pointe Coupee Parish and others in Louisiana, and also used national and state archives in France, Spain and Texas. Finding that French and Spanish records had more details about the origins and individual characteristics of slaves than did those of the British and Americans, she developed important material on the cultures of Africans in Louisiana, documenting many individuals as part of specific ethnic cultures on the African continent.
She worked for 15 years, five years with research assistants, to develop a searchable database on more than 100,000 slaves identified in historic records. These included Africans transported to Louisiana in the 18th and 19th centuries. The material was published on a CD in 2000 by Louisiana State University Press and online in 2001 by ibiblio. The database includes such details as slave name, gender, age, occupation, illnesses, family relationships, ethnicity, place of origin, prices paid by slave owners, slaves' testimony, and emancipations of slaves. 
While an influential academic work, her book Africans in Colonial Louisiana has also become popular among jazz musicians in New Orleans.  It continues to be appreciated by Afro-Americans and many whites in Louisiana. New Orleans jazz musicians refer to it as the "purple book". It is an important starting point for people who want to learn more about African-American culture in Louisiana and elsewhere.
In 2010 Midlo Hall accepted a position as Professor of History at Michigan State University, where she devotes most of her time to Biographies: The Atlantic Slave Database Network. Walter Hawthorne, Chair of the History Department, is co-principal investigator of this project. MATRIX provides the technology, hosting and storage. The project was initially funded by a contract from the National Endowment for the Humanities.
Midlo Hall's work has been distinguished by her use of original language archives in France and Spain, as well as of records in Latin America, providing a broad base for comparison of slavery in different societies. She has published internationally in English, French, Spanish, and Portuguese, and lectured internationally in English, French and Spanish. 
Midlo was married before 1951. Her oldest son Leonid Avram Yuspeh was born in Paris, France in 1951 from this marriage.
After divorce, she next married Harry Haywood in 1956. He was a political activist, member of the Communist Party, USA, and theoretician of self-determination for the African-American nation of the Deep South. She changed her name at marriage to conform to his legal birth name of Haywood Hall. They were married until his death in 1985.
Two children were born from this marriage: Dr. Haywood Hall, a world-renowned international emergency physician, and Rebecca Hall, an attorney with a Ph.D. in history .
Between 1953 and 1964, Midlo Hall collaborated with Haywood in freelance writing about theoretical aspects of the civil rights and black protest movement in the United States. Some of these articles were a joint publication in several issues of Soulbook Magazine, which began publication in Berkeley, California in 1964.   
The Gwendolyn Midlo Hall papers (1939–1991) are housed at the Bentley Historical Library at the University of Michigan  and later ones associated with her work on Africans in Louisiana at the Amistad Research Center at Tulane University.
The Harry Haywood papers are housed at the Bentley Historical Library and the Manuscript, Archives, and Rare Books Division of the Schomburg Center for Research in Black Culture, New York Public Library.
- Social Control in Slave Plantation Societies: A Comparison of St. Domingue and Cuba (Baltimore, MD: Johns Hopkins Press, 1971)
- Africans in Colonial Louisiana: The Development of Afro-Creole Culture in the Eighteenth Century (Baton Rouge, LA: Louisiana State University Press, 1992) (This won nine book prizes, including the John Hope Franklin Prize of the American Studies Association.)
- Love, War, and the 96th Engineers (Colored): The New Guinea Diaries of Captain Hyman Samuelson During World War II (editor; University of Illinois Press, 1995)
- Louisiana Slave Database and Louisiana Free Database 1819-1820, in Hall, Databases for the Study of Afro-Louisiana History and Genealogy, Compact Disk Publication (Louisiana State University Press, 2000)
- Slavery and African Ethnicities in the Americas: Restoring the Links (Chapel Hill: University of North Carolina Press, 2005)
"Escravidão e etnias africanas nas Américas: Restaurando os elos. (Editora Vozes Limitada, Brazil, Nov 8, 2017.)"
- A Black Communist in the Freedom Struggle: The Life of Harry Haywood. (Minneapolis: University of Minnesota Press, 2012)
- "Negro Slaves in the Americas", Freedomways, Vol. 4, No. 3, Summer 1964, pp. 296–327.
- "Detroit's Moment of Truth", Freedomways, Vol. 7, No. 1, Fall 1967.
- "St. Malcolm and the Black Revolutionist", Negro Digest, November 1967.
- "Black Resistance in Colonial Haiti", Negro Digest, February 1968.
- "Race and Class in Brazil", Freedomways, Vol. 8, No. 1 (Winter, 1968).
- "The Myth of Benevolent Spanish Slave Laws", Negro Digest, March 1969.
- "Africans in the Americas", Negro Digest, March 1969.
- "Rural, Black College", Negro Digest, March 1969.
- "Junkie Myths", The Black Liberator, July 1969.
- "Mechanisms for Exploiting the Black Community", Parts 1 and 2, Negro Digest, October and November 1969.
- "What Toussaint L'Ouverture Can Teach Us", Black World, February 1972.
- National Endowment for the Humanities "We the People Fellowship" 2006-07
- Distinguished Service Award, Organization of American Historians (2004)
- Knight of the Order of Arts and Letters, elected by the National Assembly of France (1997)
- Guggenheim Fellowship, 1996
- Amy Wold, " Courthouse Records Reveal Trove of Data About Slavery[ permanent dead link]", The Advocate, Feb. 18, 2001.
- Erin Hayes, "Rescuing Louisiana Pasts: Research Yields Treasure Trove of Data on Slaves", ABC News, July 30, 2000.
- David Firestone, "Identity Restored to 100,000 Louisiana Slaves", The New York Times.
- Jeffrey Ghannam, "Repairing the Past", American Bar Association Journal, November 2000[ dead link]
- "Southern Negro Youth Congress (1937-1949)", BlackPast.org.
- Ned Sublette, "Interview with Gwendolyn Midlo Hall", Afropop Worldwide, 2005.
- Rediscovering America: Thirty-Five Years of the National Endowment for the Humanities. Report to Congress pursuant to PL 101-152. ISBN 0-942310-02-0, p. 19.
- " Hon. Major R Owens of New York. Recognizing the Shared History of Slavery of France and the United States", Congressional Record, Proceedings and Debates of the 109th Congress, Second Session, May 10, 2006. House of Representatives.
- Firestone, David (2008-07-30). "Identity Restored to 100,000 Louisiana Slaves". The New York Times.
- "Gwendolyn Midlo Hall", JRank Encyclopedia, accessed 17 Jan 2009.
- Midlo Center for New Orleans Studies at the University of New Orleans, accessed 30 May 2017.
- Jacqueline Dowd Hall, "The Long Civil Rights Movement" Archived 2008-10-12 at the Wayback Machine.
- Eric C. Schneider. Smack: Heroin and the American City, Philadelphia: University of Pennsylvania Press, 2008., ISBN 978-0-8122-4116-7, pp. 40, 169-72. pp. ix-xvi, 1-259
- Hall, "Rural, Black College", Negro Digest, March 1969.
- http://picasaweb.google.com/lh/emailAlbum?uname=ghall1929&aid=5307644475055127297[ permanent dead link]
- "African American Organizations and Leaders: Civil Rights Leaders". Bentley Historical Library (University of Michigan). Archived from the original on 2010-06-07.
- Gwendolyn Midlo Hall collection, Bentley Historical Library.
- Freedom of Information Act files for Gwendolyn Midlo Hall; Gwendolyn Midlo Hall collection, Bentley Historical Library
- Gwendolyn Midlo Hall collection, Bentley Historical Library
- "Slavery" Archived 2009-01-25 at the Wayback Machine., History, Stanford University Library, accessed 15 Jan 2009
- Rowell, Charles H.; Gwendolyn Midlo Hall (Fall 2006). "Gwendolyn Midlo Hall". Callaloo. 29 (4): 1049–1055. doi: 10.1353/cal.2007.0067.
- "GWENDOLYN MIDLO HALL, Curriculum Vitae". Afro-Louisiana History and Genealogy. Ibiblio. June 2007. Some Recent Lectures. Retrieved 2011-01-24.
- University of Michigan Library
- "Harry Haywood", University of Massachusetts
Slave Biographies: http://www.slavebiographies.org/ Mellon Foundation Project: http://www.enslaved.org/