Dear William Howze,
Thank you for posting your request on History Hub!
If you have not already done so you should consult Foreign Relations of the United States (FRUS). This is a Department of State publication of selected documents from the Department’s files and other sources. Besides providing the text of the most important documents on U.S. foreign policy, FRUS also provides a source citation printed either as a header with the document or as a footnote). Those references to file numbers or other records identification are the keys to locating not only the printed documents but other documents on the same subject not selected for publication. Cited "Lot Files" may be difficult to identify among the records in the National Archives using just the Lot number. If you are interested in using any of those records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at firstname.lastname@example.org. FRUS is usually available at large universities or public libraries, and in the U.S. Government Depository Libraries.
We would also suggest that you look into records located in the Central Decimal Files, 1910-1963 in the General Records of the Department of State (Record Group 59), described here in the National Archives Catalog, particularly with regard to Class 8 in the Department of State filing manual from the 1940s outlined here. Details regarding the Department of State filing system from that time period can also be found in the information pamphlet for NARA microfilm publication M973 “Purport Lists for the Department of State Decimal File 1910-1944.” In addition, we located in the National Archives Catalog 5 series from the Interdepartmental Committee on Cooperation with the American Republics in the Records of Interdepartmental and Intradepartmental Committees (Record Group 353) that may be of interest to you.
For more information about these records, please contact the National Archives at College Park - Textual Reference (RDT2) 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 RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!