Thomas's work focuses on African American history, specifically slavery and emancipation in context of the United States of America.[2]
From 1987 to 2000 Thomas worked at the Shrine of the Black Madonna Bookstore and Cultural Center in Atlanta. Here she created the Black Holocaust Exhibit, a collection on slavery in America.[4][5][6]
From her work on the Black Holocaust Exhibit, Thomas published four interactive books on slavery and emancipation in the United States entitled:
- Lest We Forget: The Passage from Africa to Slavery and Emancipation (1997, Random House)
- Freedom's Children: The Passage from Emancipation to the Great Migration (2000, Random House)
- No Man Can Hinder Me: The Journey from Slavery to Emancipation Through Song (2001, Random House)
- We Shall Not Be Moved (2002, Random House)
Thomas also co-authored Emancipation Proclamation: Forever Free with Kevin McGruder (2013)[7] and was a contributor to Leroy Barber's book Red, Brown, Yellow, Black, White? Who's More Precious In God's Sight? (2013).[8]
Thomas was selected as one of a hundred distinguished Americans to contribute to the book Lift Every Voice and Sing: A Celebration of the Negro National Anthem (2000)[9] She also contributed a chapter to Albert Cleage Jr. and the Black Madonna and Child (2016)[10] and provided the introduction to Finding A Place Called Home: A Guide to African-American Genealogy and Historical Identity (1999).[2][11]
Thomas has contributed to various academic journals, notably the publication of The Odd Fellow City: The Promise of a Leading Black Town in the Journal of the Georgia Association of Historians.[5]
In 2012, Thomas was an expert and commentator for the PBS documentary, Underground Railroad: The William Still Story.[3]
Thomas has served as a distinguished scholar at the Penn Center in South Carolina and once served on the faculty of the University of South Carolina Beaufort.[2]
Thomas's first book, Lest We Forget, received an Alex Award in 1998 from the American Library Association.[12] Freedom's Children was a finalist for the 2000 Georgia Writer of the Year Award for Young Adult Books.[13] We Shall Not Be Moved received the 2003 Outstanding Contribution to Publishing Citation Award from the Black Caucus of the American Library Association.[14]
In 2004 she won the Award for Excellence in Research Using the Holdings of An Archives from the Georgia Historical Records Advisory Board.[13]