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The American Institute of Architects Archives
Membership file may contain membership-related correspondence, although there are few written records concerning 19th-century members. Contact the AIA Archives at archives@aia.org for further information.
Louisiana State University in Shreveport, Archives and Special Collections
Collection number 144. Nathaniel S. Allen Family Papers.
For more information see http://www.lsus.edu/offices-and-services/noel-memorial-library/library-collections/lsus-northwest-louisiana-archives