In 1789, which maritime infrastructure was federalized?

• A. Lighthouses built by the colonies
• B. Fortifications
• C. Harbors
• D. Shipyards

Answer: (A)

The main idea here is that the new federal government centralized a key navigation aid to improve safety for seafaring and commerce. In 1789 Congress created a national lighthouse system, taking control of lighthouses that had been built and run by colonial authorities and private interests. This established a uniform, federally funded program for operating and maintaining lighthouses along the coast, linking safety at sea directly to national authority. That direct transfer of responsibility for these coastal beacons is why this option is the best answer. Other maritime facilities like fortifications, harbors, or shipyards did not undergo the same nationwide, centralized takeover in that year, so they don’t fit as the defining federalization moment.