DALLAS (AP) — A Dallas school district is researching the histories of more than 20 historical figures to determine if their connections with slavery or the Confederacy should prompt consideration of removing their names from district campuses.

The Dallas Morning News reports Dallas Independent School District administrators recommended changing the names of Stonewall Jackson, Robert E. Lee, Albert Sidney Johnston and William L. Cabell elementary schools last week.

District Chief of School Leadership Stephanie Elizalde says a list of 20 additional figures has been compiled based on their varied connection with the Confederacy. She says more research is needed to determine what action should be taken.

Other names that may be considered for change include Texas revolutionary and founder Sam Houston, U.S. President Thomas Jefferson and Dallas pioneer James Gaston.