A pioneering American archaeologist working in the US southwest. He carried out stratigraphical and seriation excavations, notably of the Pueblo at Pecos, New Mexico, and combined stratigraphy with pottery typology to produce the first synthesis of southwestern prehistory. It has since been refined by dendrochronology, but it still provides the framework. Kidder's research forms the basis of nearly all later studies in the area. He later did archaeological surveys and excavations for the Maya program of the Carnegie Institution of Washington. He worked at Kaminaljuyú and Uaxactún. He was hailed for his multidisciplinary approach to archaeology and for changing American archaeology from antiquarianism to scientific discipline.