Lightships served a vital role in protecting U.S. maritime interests from 1820 to 1983. Employed as navigational aids, lightships were stationed along shipping lanes and intercoastal waterways in the Atlantic, Pacific, Gulf of Mexico, Great Lakes, and various estuarine environments in the Chesapeake, North Carolina, and the Pacific Northwest. Addressing gaps in the current historical and archaeological record pertaining to lightships, this thesis answers different research questions and discusses the role of lightships in the American maritime cultural landscape. The development of lightship construction is included as well as an explanation of changes in wooden, composite, iron, and steel techniques. Information regarding characteristic features of lightships focuses on improvements in light and fog signaling equipment. In total, this historical and archaeological study analyses use, construction, and meaning of lightships in America.