Archaeological theoritical of applicant and importance:

There is no single theory of archaeology, and even definitions are disputed. Until the mid-20th century, there was a general consensus that archaeology was closely related to both history and anthropology.

The first major phase in the history of archaeological theory in the United States developed during the late 19th and early 20th centuries. It is commonly referred to as cultural, or culture, history. It is best known for its emphasis on historical particularism.

In the 1920s in the American Southwest cultural historical archaeology was intimately tied with the direct historical approach.[16] This approach continues to be pursued in the American Southwest, the American Northwest Coast, Mesoamerica, the Andes, Oceania, Siberia, and other world areas where there appears to be continuity between living, indigenous populations and
archaeological remains of past groups. In pursuing the direct historical approach, ethnohistorical and early historical records play an important role in articulating the connections between modern people and the archaeological past. Literary sources can be used in other contexts as well, for example, in the case of Hadrian’s Wall.

In the 1960s, a number of primarily American archaeologists, such as Lewis Binford and Kent Flannery, rebelled against the paradigms of cultural history.
Archaeological theory now borrows from a wide range of influences, including neo-Darwinian evolutionary and Feminist archaeology, and Systems theory.