The Oscar W. Collet Manuscript Collection provides an insightful look at the personal and academic life of Oscar W. Collet. From his work over the years with the Missouri Historical Society to his outside personal research, this collection imparts valuable information on his life and the topics of his constant research. The collection contains items dating from 1768-1902, with most of the material spanning the period of 1880-1900.
Collet corresponded with many nineteenth century scholars and historians. Some of the more prominent correspondents include Francis Parkman and John Gilmary Shea. These correspondences can be found in the correspondence series.
Collet had several unpublished manuscripts which can be found in the manuscripts series. His biography of Julia Dean is located in this series. Also worthy of mention are Collet's novels, complete with illustrations and verses, written in his own hand.
Considered by his contemporaries to be an expert on the Louisiana Territory, Collet did extensive research on this topic. His notes and research tools, including exact copies of certain documents and manuscripts, can be found in the research notes series.