In this article, Zoe Burkholder explores the historical interplay of the emergence of tolerance education in the United States and the rise of black educational activism in Boston. By uncovering a pointed lack of tolerance education in Boston and a widespread promotion of tolerance education in other cities in the early half of the twentieth century, the author reveals how racial, historical, and political factors complicated tolerance education's local implementation in Boston. Informed by local racialized politics in the 1940s, the predominantly Irish Catholic teaching force in Boston declined to teach lessons on racial tolerance that were popular nationwide during World War II. Burkholder argues that this site of active teacher resistance against tolerance education provided fertile ground for black educational activism in Boston during the civil rights movement. These findings presage the well-documented virulence of white protest to school integration in Boston and complicate our understanding of integration in today's educational context. (Contains 37 notes and 2 figures.)