"What Was the Tulsa Race Massacre of 1921?" is a book written by Caleb Gayle and illustrated by Tim Foley. The book is part of the "What Was?" series, which is a collection of books that provide an overview of historical events and figures for children. The book covers the events leading up to the Tulsa Race Massacre of 1921, which was a violent attack on the African American community in Tulsa, Oklahoma. The book describes how a racist mob burned down homes and businesses, and killed scores of innocent residents.

In addition to "What Was the Tulsa Race Massacre of 1921?", there are other books available on the topic. "The Burning: Massacre, Destruction, and the Tulsa Race Riot of 1921" by Tim Madigan is a non-fiction book that provides a detailed account of the events leading up to the massacre and its aftermath. "The 1921 Tulsa Race Massacre" by Karlos K. Hill is another non-fiction book that provides an in-depth analysis of the massacre and its impact on the African American community in Tulsa. There are also several other books available on the topic, including "Riot and Remembrance" by James S. Hirsch and "Black Wall Street" by Hannibal B. Johnson.