Amy Greenberg, history and women’s studies professor at Penn State University, talked about her book, A Wicked War: Polk, Clay, Lincoln, and the 1846 U.S. Invasion of Mexico, in which she recounts the Mexican-American War in 1846. The author talked about President Polk’s decision to go to war and the roles that then Congressman Abraham Lincoln and Henry Clay played in the national debate. Amy Greenberg speaks at the Abraham Lincoln Presidential Library and Museum in Springfield, Illinois.