Emma Lou Thornbrough (January 24, 1913 – December 19, 1994) was born in Indianapolis, Indiana.
She was a pioneer among professional historians in African-American history, a lifelong civil-rights activist in Indiana, a professor of history at Butler University from 1946 until her retirement in 1983, and an Indiana historian and author.
Thornbrough's major scholarly contributions include several publications devoted to black history, such as The Negro in Indiana before 1900; Booker T.
Washington; T.
Thomas Fortune, Militant Journalist; Since Emancipation: A Short History of Indiana Negroes, 1863–1963; and Indiana Blacks in the Twentieth Century (published posthumously in 2000).
She also wrote Indiana in the Civil War Era, 1850–1880, among other scholarly publications.
In addition to her writing and research, Thornbrough was well known as a social activist and was especially active in Indianapolis civil rights groups, including the Indianapolis Human Relations Council, which she helped organize; the Indiana Civil Liberties Union; and the Indianapolis National Association for the Advancement of Colored People.