archaeological work was Gamio’s excavations of the Ciudadela complex in the center of Teotihuacán where he uncovered key information concerning the origins of the ancient city.

During the same period, Gamio organized several other archaeological projects including excavations of the main plaza of Tenochtitlán and important studies of the early sedentary, or archaic, cultures in the basin of Mexico. Gamio collaborated with B. Cummings in excavations of the early urban site of San Cuicuilco, which had been nearly covered by ancient lava flows. After the 1920s, Gamio devoted most of his efforts to social anthropology and to setting up government programs to improve the living conditions of Mexico’s indigenous peoples. He founded the National Institute of Indigenous Groups and directed it and other institutes for many years. He is one of the key figures of Mexican anthropology during the twentieth century, and his thinking strongly influenced government policy concerning the pre-Hispanic past and the problems of contemporary indigenous people.

In 1915, Herbert Spinden published an influential synthesis of early cultures in the Americas that was partly inspired by the studies of Gamio and others of Mexico’s archaic cultures. Spinden’s work contained hypotheses about the origins of agriculture and sedentary populations and caused a controversy among archaeologists that lasted for several decades (Willey and Sabloff 1980). Spinden’s other fundamental contribution was his doctoral thesis (Spinden 1913), which was one of the key early analyses of Maya civilization and provided a corpus of monuments in chronological order determined by dated inscriptions and styles using his own Maya calendar correlation. In this work, Spinden proposed that the basic content of the inscriptions is historical and that the major Maya sites were true cities, not just ceremonial centers. These ideas were criticized by distinguished Mayanists like Morley and j. e. s. thompson, and nearly fifty years passed before most investigators realized that Spinden was correct (Marcus 1983).

In 1914, Morley obtained long-term support from the Carnegie Institution for an ambitious program of multidisciplinary studies of the Maya. The Carnegie program, which lasted for over forty years, was directed successively by Morley, alfred v. kidder, and H.E.D. Pollock and organized important archaeological projects in Mexico, Guatemala, and Honduras. Its staff included many notable archaeologists: J.E.S. Thompson, tatiana proskouriakoff, Ricketson, Ruppert, Morris, Wauchope, A.L. Smith, R.E. Smith, the great linguist Ralph Roys, and others. For nearly thirty years, Morley explored the Maya lowlands and recorded hundreds of inscriptions, which were published in five volumes (Morley 1938).

The principal Carnegie project in Mexico during the 1920s involved the excavation and restoration of buildings at Chichén Itzá (Morris, Charlot, and Morris 1931; Rubbert 1952), and during the same decade, the number of archaeological projects in the central Mexican highlands increased. Initially these were led by Gamio, as “director of anthropology” for the federal government, and later they continued through the efforts of Ignacio Marquina, head of the national Department of Pre-Hispanic Monuments founded in 1925. In 1923, Marquina, trained as both an architect and an archaeologist, began a project at the Aztec center of Tenayuca and achieved a thorough analysis of the construction phases and ceramic sequences of the main pyramid and associated structures (Marquina et al. 1935). Marquina’s program at Tenayuca produced one of the best architectural restorations in Mesoamerica.

Eduardo Noguera was responsible for ceramic analyses in Tenayuca. During the 1920s he excavated at Teotihuacán and surveyed a series of archaic (formative) sites in the basin of Mexico including Zacatenco, Ticoman, and El Arbolillo, which were subsequently excavated by George Vaillant. Noguera successfully used seriation techniques on surface collections at early sites and published a book on the archaic cultures of the basin in 1925. Also during the 1920s, Tulane University organized an archaeological and ethnographic survey of Tabasco, Chiapas, and southern Veracruz directed by Blom and La Farge. The first detailed descriptions of gulf coast olmec centers, especially la venta, Tabasco, were published, and thus the debate concerning the possible roles of the Olmec in