Du Bois was a prolific author. His collection of essays, The Souls of Black Folk, was a seminal work in African-American literature; and his 1935 magnum opus Black Reconstruction in America challenged the prevailing orthodoxy that blacks were responsible for the failures of the Reconstruction era. He wrote the first scientific treatise in the field of sociology; and he published three autobiographies, each of which contains insightful essays on sociology, politics and history. In his role as editor of the NAACP's journal The Crisis, he published many influential pieces. Du Bois believed that capitalism was a primary cause of racism, and he was generally sympathetic to socialist causes throughout his life. He was an ardent peace activist and advocated nuclear disarmament. The United States' Civil Rights Act, embodying many of the reforms for which Du Bois had campaigned his entire life, was enacted a year after his death.