[Note: Far more exhaustive and comprehensive accounts of the discipline exist, such as Trigger's A History of Archaeological Thought. Although a nuanced understanding of archaeological theory is not necessary for proper curation, a broad understanding of the different eras of collecting is necessary to differentiate the many different kinds of collections in need of care. This section is written from the perspective of Midwestern archaeologists to be illustrative of general trends in the discipline while avoiding modest regional differences that obfuscate larger trends. Similar, but not identical trends, occurred throughout other regions (see Chapter 2 in Sullivan and Child's Curating Archaeological Collections). There are some distinctions between regions based on independent factors, such as the large percentage of federally owned land in the western United States versus the relatively small amount in the east. The purpose in focusing on the Midwest is to present a cohesive narrative that illustrates how and why archaeological collections were generated for extremely different intellectual purposes and how collecting practices were shaped by larger changes in theory and the structure of the discipline.]
American archaeology emerged from a non-scientific antiquarian origin that bears little resemblance to the profession as it exists in the modern era. Prior to the twentieth century, most collections were recovered in non-systematic excavations generally equivalent to modern looting. In addition to trophy hunting by local collectors, some collecting was also undertaken for what might be described (at the time) as more scholarly pursuits. The primary scholarly question of regional and national interest was the identity of the mysterious "Moundbuilders" of the eastern states, whom many at the time speculated were an advanced civilization that had been destroyed by primitive invaders. The "Myth of the Moundbuilders" required guilty parties and as a result, the racist labels of "savages" and "barbarians" were readily applied to the Native American tribes who were presumed to have destroyed the (supposedly) culturally superior Moundbuilders. The speculative and romantic notion of the lost Moundbuilders generated great public interest in determining their identity and fate. Some of the earliest (mid to late nineteenth century) collections were used to either promote or discredit the Moundbuilder myth. Most were personal collections obtained from mortuary contexts in earthen mounds. Other than a few notable exceptions, most have since been dispersed although a few collections or individual artifacts made their way into the care of museums.
In the Middle Ohio River Valley where the Lichliter project takes place, the widespread looting of archaeological sites was especially rampant in the late nineteenth century as collections were procured in haste for exhibition at the 1893 World's Columbian Exposition, for the collections of large museums, and for personal collections. Antiquarians (e.g. Ohio's Warren K. Moorehead) were primarily interested in objects of high aesthetic value or exotic origin and recorded only minimal information about where those objects were found. Although not necessarily at odds with popular expectations of the era, the disturbance of human graves (usually in burial mounds) to acquire the most attractive or unusual objects was especially callous and narrow-minded. The pursuit of archaeological objects as personal or institutional trophies was common and minimal contextual data was collected or maintained in this era. Although many of these late-nineteenth collections are extant in museum collections and these artifacts continue to be re-examined with emerging technology, their unfortunate lack of contextual data precludes a complete understanding of their cultural use and significance. In most cases, maps and associated documentation were of minor concern during excavation.
As the twentieth century dawned, American archaeology began to emerge as a more serious scholarly discipline as museums began to play a less dominant role and field archaeology became practiced increasingly by university researchers and investigations undertaken or funded by government entities. The completion of an exhaustive study by Cyrus Thomas in 1894 compelled the scholarly community to acknowledge that the prehistoric mounds and other sites spread across the United States were in fact the work of Native American ancestors, which brought about many new questions. For example, if Native Americans had built these monuments and impressive constructions, why was there seemingly so little extant cultural knowledge of their purpose and meaning? If perhaps these sites had been created in deep antiquity, what depth of time was represented? How long had these people been here? Were these ancient builders similar to or different from descendent groups? The discovery of human artifacts in association with extinct Pleistocene ("Ice Age") mammals in the late 1920s was especially shocking as it was unambiguous evidence that prehistoric populations had been present in North America for more than 10,000 years. Scholars increasingly recognized that these sites represented not only an immense depth of time, but also significant change over time as different groups occupied the same landforms but practiced different behaviors. Following the lead of European scholars, attention began to be paid to concepts like stratigraphic position as an indicator of the sequences of cultures over time. Temporal relationships were often poorly or erroneously understood, but were a high priority and compiled in earnest.
In the 1930s, the Great Depression brought high unemployment across the United States. The federal government responded with the New Deal program, an economic stimulus intended to employ laborers in a variety of pursuits that could advance the public good. The Works Progress Administration's (WPA) archaeology program (and others) resulted in an unprecedented amount of archaeological fieldwork led by some of the country's best and brightest minds. Although concentrated in the southeastern United States (where an abundance of both mounds and warm year-round weather are found), these programs yielded new and extensive collections along with associated contextual data from across the country. Although much of the work was conducted by unskilled laborers, the resulting collections were the product of systematic excavation methodologies even if they might be simplistic in comparison to more modern excavations. These methodologies were used to record provenience data about artifacts and the larger characteristics of sites themselves as represented by features, stratigraphy, and spatial relationships.
The first half of the twentieth century yielded data that was used primarily to establish "culture history" - the who/what/when/where of prehistory (note that "why" is excluded). Archaeological data was used at a broad level to define the occurrence of recurring artifact types and behavioral traits across time and across geographic expanses (e.g. river valleys). These types and traits were regarded as proxies for common "normative" behaviors and group identities; such commonalities were deemed more important than recognizing variation. Archaeology was not yet practiced as or considered a science by many of its own practitioners, as the focus on defining culture history was descriptive, but not explanatory. Many practitioners of the era did not consider archaeological data as having potential beyond timelines, trait lists and classifications, which were produced in quantity.
By the 1940s and 1950s, some anthropologists promoted the concept of culture as a non-biological form of adaptation to the natural environment, which led to increased interest in the culture ecology of modern and ancient populations (e.g. How do populations change in response to changes in the environment? How do they in turn modify the environment?) This notion filtered into archaeological inquiry by the 1960s and stimulated new interest in understanding prehistoric environments as they are represented in the archaeological record by ecofacts and other data. Excavations of mounds and mortuary sites continued, but there was also growing interest in finding and excavating habitation sites where basic information about economy and subsistence could be found. Although habitation sites had always been exploited, investigators increasingly made efforts to collect or note the more mundane artifacts and ecofacts of habitation sites. This interest became increasingly feasible with development of flotation in the 1960s; a new method for collecting carbonized plant remains that would previously not have been recoverable.
The invention of radiocarbon dating in the late 1940s was a major technological breakthrough in the dating of sites and cultures. Prior to radiocarbon dating, most of the temporal aspect of American archaeology was limited to relative dating: understanding sequences of cultural phenomenon through stratigraphic excavation, which was not always feasible in regions like the Midwest which lack deep, stratified sites. Radiocarbon dating offered a new opportunity for calendrical dating, which resulted in increased collection of datable archaeological ecofacts like wood charcoal, nuts, and seeds. Early radiocarbon dates were often unreliable in comparison to the more technically sophisticated methods employed today, but were still useful in providing a temporal dimension that was previously lacking in regions like the Midwest.
The Processual Archaeology of the 1960s was the culmination of many evolving ideas about the purpose, role, and goals of American archaeology. As a result, American archaeology began to diverge from the rest of the discipline as it is practiced in all other countries, where it is generally seen as an extension of history. Modern American archaeology is the fusion of a humanities and scientific approach, which was the result of conceptual changes to the discipline that had been building for some time and were popularized around the 1960s. During this time, Processual Archaeology (i.e. the "New Archaeology") emerged and was popularized by Willey and Phillips, Lewis Binford (coincidentally a close personal friend of Virginia Gerald whom excavated the Lichliter site), and others. At this important juncture, American archaeology became inextricably linked with anthropology and became focused on describing how and why cultures change (i.e. "process") among other theoretical concerns.
Processual Archaeology was the intersection of a variety of theoretical concepts that changed the practice of archaeology by advocating positivist hypothesis testing and the application of ethnohistoric models. One of the most important concepts for field methodology was the idea that spatial provenience was a physical reflection of behavior and relationships as they actually were practiced in antiquity. For example, one of Binford's most infamous studies was a first-hand observation of Nunamiut (Eskimo) hunters butchering caribou in which he recorded the distribution of different skeletal elements as the hunters processed and discarded them. Binford then applied this as a model to interpret a Mousterian (Pleistocene/"Ice Age") assemblage from France where similar animal butchering had taken place in antiquity.
An alternative to Processual Archaeological began to develop in the 1970s and by 1985, a new approach labeled "Post-Processual Archaeology" emerged, advocated by theorist Ian Hodder and others. Proponents argued that Processual Archaeology was environmentally deterministic and rejected systems theory, cultural materialism, and cultural ecology – these ideas treated culture change as external and regarded humans as passive objects molded by outside forces. Post-Processual archaeologists called for a more dynamic model of culture, instead of the passive model of normative and ecological paradigms. They recognized the human capacity to create and modify idea systems as an important source of how societies operate and change.
Many modern American archaeologists identify their theoretical approach as "Processual Plus," which reflects a modification rather than an outright rejection of Processual ideas. For example, although Processualism may have over-sold the interpretive potential of the ethnohistoric approach, the importance of intrasite spatial provenience (as well as context and association) remains an important priority of modern American archaeology. Most changes to archaeological field and lab methodology since the 1960s relate more directly to changes in technology and the nature of the profession itself rather than to shifts in theoretical stance or the types of information being collected.
Perhaps the largest change of the past fifty years of American archaeology is the birth and growth of the Cultural Resources Management (CRM) industry. In regard to archaeology, CRM is government-mandated archaeological practice that is often legally required when a project utilizes public land, public funding, or requires federal permitting. CRM has grown substantially since the 1970s and now accounts for about 90% of all archaeological fieldwork. The majority of CRM archaeological fieldwork is survey (which increasingly includes geophysical survey) with additional sampling and evaluation when potentially significant resources are detected. Some sites are deemed significant and in these cases, CRM companies are directed to mitigate the impending destruction or alteration of cultural resources. This mitigation often employs excavation as method for recovering information from the archaeological record.
The growth of the CRM industry produced massive amounts of new archaeological collections and has exacerbated an already significant curation crisis. Although the disposition and curation of CRM-generated collections was not always accounted for in the early years of the industry, this began to change in the 1990s. Modern CRM projects usually address the curation of recovered objects and many of these collections are then sent for permanent storage at museums and other qualifying repositories. These collections are normally inventoried prior to transfer and may even be organized, labeled, and placed in storage mediums by the CRM company following the directions of the intended curation facility. In other cases, the collection will be processed by the curation facility after transfer. In the modern era, CRM collections tend to be fairly well inventoried and organized since these projects usually require a quick turn-around in analysis, reporting of results, and determining the disposition of collections and data. Until recently, most CRM collected information was in paper analog format, but a transition to born-digital data collection has already begun by many larger CRM companies. Born-digital data invites its own set of curation issues as the profession struggles to deal with rapid changes in technology, storage mediums, software, and the long-term preservation of digital information.