Schools are not adequately teaching the history of slavery in the United States and the impact it continues to have on race relations, a report from the Southern Poverty Law Center finds. Based on a survey of high school seniors and social studies teachers, as well as an analysis of fifteen state standards and ten widely used U.S. history books, the report, Teaching Hard History: American Slavery (52 pages, PDF), found that teachers were neither prepared nor provided sufficient materials to teach the history and legacy of slavery. While 97 percent of the teachers in the survey agreed that learning about slavery was essential to understanding U.S. history, 58 percent found their textbooks inadequate and 39 percent said their state offered little or no support for teaching the topic. Of the high school seniors in the survey, only 8 percent identified slavery as the central cause of the Civil War, less than half (44 percent) knew that slavery was legal in all colonies during the American Revolution, and 68 percent did not know that a constitutional amendment formally ended slavery in the U.S. The report calls on textbook authors, curriculum developers, and states to use original historical documents to better represent diverse voices; connect past and present by showing both the contribution of enslaved people to and the legacy of slavery in American society; and provide enhanced curriculum requirements and supporting frameworks through state standards.