By the 1890s, the neighborhoods had a negative reputation in terms of crime, poverty, and mortality.[42] W.E.B. Du Bois, in his pioneering sociological study The Philadelphia Negro (1899), undermined the stereotypes with experimental evidence. He shaped his approach to segregation and its negative impact on black lives and reputations. The results led Du Bois to realize that racial integration was the key to democratic equality in American cities.[43]