Natural history in Iowa prior to the 20th Century can be conveniently arranged into 4 phases: Native American, before the Louisiana Purchase, between the Louisiana Purchase and about 1850, and after 1850. Native American natural history was extensive and had a distinctly spiritual character. Natural history was a component of European exploration up to the time of the Louisiana Purchase, but was not treated as a separate endeavor; the evidence from this period comes from the journals and diaries of early exploreres, fur traders and the like. Between the Louisiana Purchase and about 1850, natural history changed from its status as an adjunct to geographic exploration, for instance government sponsored expeditions along the rivers and Army excursions into the interior, to systematic research with natural history as the primary goal. During this period, descriptions of natural history moved from being parts of exploration narratives to reports on natural history itself. After 1850, natural history in Iowa encompassed organized, systematic efforts to record the geology, environment and biota of the state
