Dear Mr. Keith,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located Inmate Case Files, 1902 - 1922 in the Records of the Bureau of Prisons (Record Group 129) but we were unable to locate a case file for your grandfather. We also located Index to Prisoners, 1902 - 1973 for the U.S. Penitentiary, Atlanta in Record Group 129 that may have a listing for your grandfather. For more information about these records, please email the National Archives at Atlanta (RE-AT) at firstname.lastname@example.org.
Also, the National Archives at Kansas City (RM-KC) has a copy of the Bureau of Prisons microfilm publication entitled "Index to Released Federal Prisoners, 1911-1974." For more information, please contact RM-KC at email@example.com.
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 RE-AT and RM-KC. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your family research!