W. E. B. Du Bois 
Souls of Black Folk [PDF ebook] 
Essays and Sketches

The Souls of Black Folk is the seminal work by Du Bois on race in late 19th-century North America. The way we think about and examine race today stems from his ideas. He spoke of the "double-consciousness, this sense of always looking at one’s self through the eyes of others, " and of the progress and obstacles to progress of the black American.