Augustus and Alice Dixon Le Plongeon entered American archaeology at a critical juncture in its development.  Archaeology was developing as an academic discipline, moving from speculation to description and gathering of facts.  By the last quarter of the century the field was formalizing, and the self-trained archaeologists were being replaced by university trained professionals.

As early as the 1840s, influential men in the field, such as Joseph Henry of the Smithsonian Institution, admonished researchers not to speculate on Precolumbian American civilization, but to wait until all the "facts" were in.  In his 1857 Observations on Mexican History and Archaeology, Branz Mayer wrote,
 

The American antiquarian should, as yet, avoid the peril of starting in his investigations
with an hypothesis, for the chances are very great that, in the mythic confusion of our
aboriginal past, he will find abundant hints to justify any ideas excited by his credulity and
hopes.  In the present state of archaeology, all labors should be contributions to that store
of facts, which, in time, may form a mass of testimony.

Several early researchers and explorers were key figures in the early development of Maya research.

Jean Frederick Waldeck, who worked in the Maya area in the 1830s, documented the ruined cities on the Yucatan Peninsula by illustrating hundreds of structures and motifs.   He was later criticized as being too interpretive in a number of his drawings, as well as for proposing Asiatic origins for the Maya.

Following closer the dictates of the times, John Lloyd Stephens and Frederick Catherwood achieved great success in producing beautifully illustrated books of their travels in Yucatan and Central America.  They knew the value of photographs in documentation and attempted to use the daguerreotype photographic process, but found it difficult to use in the field.  Catherwood finally resorted to the camera lucida, a well proven method that allowed the illustrator to trace the image directly onto paper.  His color drawings were an impressive and important step in the documentation of the archaeological sites, but they lacked the detail of a photograph and were often romantic in style.  Their purpose was not only to record, but also to impress the viewer.  And, their text conformed to the admonishments of men like Henry, avoiding almost all speculation or interpretation.

During the second quarter of the nineteenth century, the scholar Brasseur de Bourbourg spent a number of years in the Maya region.  As a result of that fieldwork, he wrote the Four volume Histoire des nations civilisees du Mexique et de l'Amerique centrale in 1856. At the time of its publication it was well received by scholars, albeit reluctantly, because its conclusions were based on limited factual knowledge. Later he published his Quatre lettres sur le Mexique, and was severely condemned as being overly speculative in promoting the hypothesis that America was the mother continent of world civilization.

In the 1860s, Desire Charnay, a French photographer, documented the Maya ruins using the new glass-plate negative process that had been developed a decade earlier.  His work produced the first successful and widely known photographs of these structures.  While the quality of his photographic work was excellent, his short stays at the various ruins limited the number of photographs he took, and prevented systematic recording.  His intent was to provide views of the ruins, rather than an in-depth documentary record of the sites.

While Charnay's writings fell within the bounds of description, he attempted to provide some interpretation.  It consisted mainly of comparing Mesoamerican cultures with the civilizations of Asia, and identifying the Toltecs of Highland Mexico as the civilizers of Mesoamerica, a theory that has never found any support.

In 1873, the Le Plongeons landed in Yucatan prepared to document the ruins by the same new photographic method Charnay had used and by making architectural plans and drawings. Augustus felt well prepared for what he saw as his life's work.  He brought years of experience in surveying and photography, most recently in Peru, and he, unlike his predecessors, brought with him a hypothesis to be tested by systematic observation.  He openly stated that he came to Yucatan with the hypothesis that the Maya were the founders of world civilization.  He would let the "facts" either prove or disprove that hypothesis.