The relationship between welfare and racial inequality has long been understood as a fight between liberal and conservative forces. In The Segregated Origins of Social Security, Mary Poole challenges that basic assumption. Meticulously reconstructing the behind-the-scenes politicking that gave birth to the 1935 Social Security Act, Poole demonstrates that segregation was built into the very foundation of the welfare state because white policy makers--both liberal and conservative--shared an interest in preserving white race privilege.

Although northern white liberals were...