significant protection. This process helps decide different approaches and solutions to the project, but does not prevent any site from demolition or alteration. Motives Early preservation efforts were driven by patriotism and a desire to protect the new establishment of the nation by wealthy, private individuals. Early efforts focused primarily on individual structures as opposed to areas such as a neighborhood in a city or a rural landscape. The preserved structures were often turned into museums to create a showcase and generate tourism. The focus of preservation eventually shifted from patriotism to the aesthetics of a structure or area and ultimately to their structural relationships with society at large. According to Robin Elizabeth Datel, modern motivations for preservation can be summed up in four points: to retain diverse elements of past to perpetuate the distinctive identities of places to involve amateurs in landscape care to practice a conservation approach to environmental change. The economic benefits of preservation continue to become more important and better understood and documented. Preservation efforts produce the most jobs in the nation's economy and these jobs create new businesses and tourism, increase property values, and enhanced the quality of life in a community. Effects The National Historic Preservation Act has led to major changes in the employment trends in historic preservation fields. Archaeologists, historians, historic architects, and others have been employed in vast numbers in the field of cultural resource management. Cultural resource management is an umbrella term that encompasses archaeology, historic preservation and other disciplines when employed for the purposes of compliance with NHPA and other federal and state-mandated historic preservation laws. Prior to the passage and subsequent enforcement (through litigation) of the National Historic Preservation Act of 1966 and other laws, most archaeologists, historians, and other historic preservation specialists were employed primarily in the field of academia, working at universities or other places of higher learning. However, since the passage of the NHPA, ever-increasing numbers of these professionals are employed in support of the cultural resources management industry. Large public works projects often require that teams of archaeologists perform limited excavations in order to properly inventory buried archaeological remains and assess their eligibility for the National Register of Historic Places. This industry has also allowed a larger swath of individuals to participate in archaeology and history as, unlike in the academic arena, a PhD is not required to earn a professional livelihood. The Secretary