This paper present an explanation for the variation in date of enactment of compulsory school attendance legislation. Enactment of compulsory schooling is interpreted in terms of resources committed by states to sustain public schooling for all. Using data drawn from the 1870 Census on populations and occupations, the paper analyzes specific conditions favorable to the commitment of such resources. the interaction of percent of males in agriculture with the ratio of school-age children to adult males is the strongest predictor of date of enactment. The second strongest predictor is the date of formation of State Teachers Associations. These variables, along with the recognition of regional difference, constitute the strongest and most parsimonious explanation for variation in timing of enactment. Their relation to theoretical interpretations of compulsory schooling is discussed.