Hi Mr. Jones,
I found an article about John J VanderKemp that might interest you https://chroniclingamerica.loc.gov/search/pages/results/?state=&date1=1789&date2=1963&proxtext=+John+J.+Vanderkemp&x=13&… .
Best Wishes and good luck in your search.
Dear Mr. Jones,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located Domestic Letters, 1784 - 1906, Letters Received, 1789 - 1906, and Despatches from U.S. Consular Officers, 1789 - 1906 in the General Records of the Department of State (Record Group 59) that may have correspondence concerning the death. We also located United States Diplomatic Records for Mexico, 1825 - 1940 in Records of the Foreign Service Posts of the Department of State (Record Group 84). Portions of the first two series have been digitized and may be viewed online using the Catalog. For more information about the non-digitized records, please contact National Archives at College Park - Textual Reference (RDT2) via email at Archives2reference@nara.gov.
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We hope this is helpful. Best of luck with your research!