Duchenne muscular dystrophy is the most common neuromuscular genetic disorder. This review describes the identification of the cause of the disorder in the late 1980s—dystrophin deficiency—and the emerging therapeutics enabled by increased understanding of dystrophin structure and function. Image from Duchenne, Guillaume‐Benjamin (1868). "De la paralysie musculaire pseudo‐hypertrophique, ou paralysie myo‐sclérosique". Arch. Gen. Med. Bibliothèque nationale de France. 11: 5–25, 179–209, 305–321, 421–443, 552–588. Duchenne muscular dystrophy was a well‐established medical and genetic enigma by the 1970s. Why was the new mutation rate so high in all world populations? Why were affected boys doing well in early childhood, but then showed relentless progression of muscle wasting? What was wrong with the muscle? The identification of the first fragments of DMD gene cDNA in 1986, prediction of the entire 3685 amino acid protein sequence, and production of antibodies to dystrophin, both in 1987, provided key tools to understand DMD genetics and molecular pathology. The identification of dystrophin nucleated extensive research on myofiber membrane cytoskeleton, membrane repair, muscle regeneration, and failure of regeneration. This in turn led to molecular therapeutics based on understanding of dystrophin structure and function. This historical perspective describes the events surrounding the initial identification of the dystrophin protein.