The publication of Travis Hirschi's Causes of Delinquency in 1969 was a watershed moment in criminology. There are many reasons for the work's lasting influence. Hirschi carefully examined the underlying assumptions of extant theories of crime in light of what was known about the individual-level correlates of offending. He then developed critical tests of hypotheses derived from social control theory and competing perspectives and empirically assessed them using original self-report delinquency data. Many of his key findings, such as the negative correlation between attachment to parents and delinquency, are now established facts that any explanation of crime must consider. Causes of Delinquency is still cited hundreds of times per year, and it continues to spark new research and theoretical development in the field. Perhaps the most lasting legacy is the volume of criticism it has attracted and fended off, leading to its enduring contribution to the study of crime and delinquency.