Editors' Summary: Despite its importance, historic preservation is an unfamiliar area to many environmental lawyers. The 1966 National Historic Preservation Act requires federal agencies to consider and, where possible, minimize the impacts of their actions on historic properties and sites. Harm to historic properties is among the environmental impacts to be considered in NEPA procedures as well. The author reviews the development and status of federal historic preservation law as it is spelled out in statute and executive order, and as it has been interpreted in over 80 federal court decisions. The Article is a useful reference for those dealing regularly with historic preservation issues and a handy introduction for those whose practice brings them into contract with historic preservation for the first time.