Maintenance of aids to navigation had been assigned to the federal government from the beginning, first under the Department of the Treasury, and then under the U.S. Lighthouse Board (1852-1910) and its successor, the U.S. Lighthouse Service. In 1939 lighthouses were placed under the authority of the United States Coast Guard, which also took over the manning of lights with keepers. Throughout this period the expense of maintaining and staffing lights was constantly stressed. Automation of lights began early in the twentieth century, and a major push in the early 1960s relieved all but a few lighthouses of their keepers.