In North America and around the globe, archaeologists assess and sometimes excavate sites where new roads, subways, offce buildings, and arenas—just about any major construction project—are about to be built. Following local and national laws, this work balances development with the preservation of sites that have cultural or archaeological significance. Professional archaeologists working for city, state, and federal agencies, as well as cultural resource management (CRM) firms, undertake these projects, which are often called rescue excavations. Frequently, they make important discoveries in the course of their work.
In my own field of maritime archaeology, some of these discoveries have been transformative. For example, Rome’s Leonardo da Vinci Airport, begun in the late 1950s, was constructed partially over the enormous harbor built by the first-century A.D. emperor Claudius. At the time,…