Drunkenness and senility were recognized early as the basis of a staggering gait. To these were added venereal excesses, hence syphilis. Medical and scientific concerns began to be focused on "locomotor ataxia" in the 19th century with the systematic development of neuroanatomy and physiology. Rolando and Flourens were followed by Romberg and Todd, and later Friedreich, who all gave the spinal cord temporal precedence as a culprit over the cerebellum--and there were some forerunners. New spinal sensory pathways were delineated by Goll, Flechsig, and Gowers. In France, we must specially credit Duchenne as well as Bouillaud, and later Babinski, Marie, and Dejerine, for correcting, differentiating, extending, and underpinning current concepts. Failures of input and output, of conduction and central coordination were invoked and explained, among them the vestibular apparatus, as well as the causation by neoplasms, demyelination, degeneration, and infarction affecting even the frontal lobe, thalamus, and basal ganglia. Clinical testing was brought up to 20th-century standards essentially by Sherrington and Bárány, followed by Dandy, the neurosurgeon who showed how to replace ventricular fluid by air, more recently made obsolete by modern roentgenographic procedures. And tabes dorsalis, once the chief culprit, has practically become a medical anachronism thanks to penicillin.