Beginning in the 1960s, historians writing about slavery, the Civil War and Reconstruction, emphasized the human advancement achieved by the abolition of slavery and the emancipation of those who had been enslaved. Historians such as James McPherson and Martin Duberman admired the abolitionists and wrote studies of them. Through the later 20th century, such historians as David W. Blight, Michael Les Benedict, James McPherson, John Hope Franklin, and Steven Hahn marshalled documentation to reject the Dunning School notion that the Reconstruction era was overwhelmingly corrupt. They evaluated the postwar period as not more corrupt than many times of social change and turmoil in American history.