Skip to Main Content
While the struggle over the use of alternating cunent (ac) versus direct cunent (dc) in the United States lasted from 1886 to 1895, the critical year was 1888. Early in 1888 the Edison dc interests first launched public attacks on the technical aspects of ac. Later they redirected the controversy, from a general consideration of comparative merits, to concentrate on only the safety issue. The decision of dc interests to launch public attacks on ac was probably caused by the success of a French copper syndicate in cornering much of the world's copper supply and forcing prices sharply upward in 1887. This made the lower copper costs of ac systems an attractive selling point and forced dc proponents to react. Thus the early months of 1888 saw a number of well-rounded discussions on the comparative merits of the two systems. The decision in mid-1888 to focus the debate on the safety issue was related to the discovery, in the spring of that year, of a workable principle for an ac ampere-hour meter (Shallenberger) and an ac motor (Tesla). The Edison interests were largely successful in focusing the polemics on the safety issue and achieved several major publicity coups (such as the use of ac for the first legal electrocution), but they were unable to match the technical improvements that by 1895 were clearly to make ac a far better system of power transmission.