Texas' Board of Education voted Friday to change the way its students learn about the Civil War. Beginning in the 2019-2020 school year, students will be taught that slavery played a 'central role' in the war. The state's previous social studies standards listed three causes for the Civil War: sectionalism, states' rights and slavery, in that order. 'What the use of 'states' rights' is doing is essentially blanketing, or skirting, the real foundational issue, which is slavery,' board member Marisa Perez-Diaz said. The board also reversed the decision to remove Hillary Clinton and Helen Keller from the curriculum. The standards go into effect at the middle and high school levels in 2019, and at the elementary level in 2020.