This article explores the historical context and institutional linkages that contributed to the genesis of special education during the early decades of this century. At the heart was the antinomy between a mandate for compulsory attendance and the practical interests for efficient school organization. The dilemma faced by city and state school systems was resolved by the successful anchoring of vocational education within public education and the scientific surety of intelligence testing. Yet key to the genesis of special education was the role of perceived gender differences. Early special education categories of backward pupils and truant and incorrigible pupils were defined by the conception of the ''bad boy,'' which linked special education to the male reformatory.