Dear Ms. Luke,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located Enumeration District and Related Maps, 1880 - 1990 in the Records of the Bureau of the Census (Record Group 29) that includes the file Enumeration District Maps for Adair County, Iowa. The file contains maps for the 1930 census. It does not include maps for 1900. There are also 1930 maps of Adair in the file Enumeration District Maps for Guthrie County, Iowa. In addition, we located Enumeration District Descriptions, 1850 - 1950 in Record Group 29 which includes textual descriptions of the 1900 and 1930 census enumeration districts. We also located Published Record Set of Decennial Census Maps, 1903 - 2002 in Record Group 29 that includes various maps regarding census findings and may include information about Adair County. These records are in the custody of the National Archives at College Park - Cartographic (RDSC). Please contact RDSC via email at firstname.lastname@example.org for more information.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDSC. We apologize for this inconvenience and appreciate your understanding and patience.
For official reports of data collected by the decennial censuses, see https://www.census.gov/prod/www/decennial.html
We hope this information is helpful. Best of luck with your research!