Dear Mr. Grothe,
Thank you for posting your request on History Hub!
We suggest that you review NARA’s Resources for Genealogists, as well as the History Hub Blog titled Suggestions and Advice for Family History Researchers. Also, the FamilySearch Research wiki for United States Genealogy may be useful.
We also recommend looking at the population schedules for the US Census for the time period that your grandfather was alive. The National Archives holds microfilmed population schedules from 1790 until 1940. I have included results of our National Archives Catalog search of decades (as well a some prior to and after) mentioned in your message: the Population Schedules for the 1890 Census; the Population Schedules for the 1900 Census, and the Population Schedules for the 1910 Census, the Population Schedules for the 1920 Census, the Population Schedules for the 1930 Census, and the Population Schedules for the 1940 Census in the Records of the Bureau of the Census (Record Group 29) that may contain information about him in the state he lived in. It would also indicate your great grandmother's marital status after your grandfather “disappeared” (married, widowed, etc.)and may be helpful with your research. The 1940 Census schedules are digitized and available using the Catalog. For more information about the non-digitized schedules, please contact the National Archives at Washington, DC - Textual Reference (RDT1) via email at firstname.lastname@example.org.
Another suggestion is to see if your g- grandfather ever served in the military and then see if he ever filed for a pension. Older military personnel records (generally prior to 1917) are held by the National Archives Textual Records Division in Washington, DC. For more information about these records, please contact the National Archives at Washington, DC - Textual Reference (RDT1) at email@example.com. Once you have established if he served in the military you can then search the National Archives Catalog to see if he ever filed a pension application.
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 RDT1. We apologize for this inconvenience and appreciate your understanding and patience.
We also suggest that you contact the State Archives or the Health Department of the State your great grandfather lived in to request a search for a death certificate. Most states began recording deaths between 1900 and 1930 so you may find something for him. Since you didn't indicate which state he lived in, here are links to NARA’s page of State Archives and the CDC’s webpage on locating Vital Records: Health Department of State. You may wish to note any name variants or broaden your search for the surrounding years. In addition, the FamilySearch Research wiki for [How to Find United States Vital Records] may be helpful.
We hope this is helpful. Best of luck with your family research!
Thanks, the family really appreciates your input! Unfortunately for us, we've already executed searches of most of the available resources you mentioned in your "resources for genealogists," although taxes and churches still hold some hope for us. Our William Palmer Gore was said (by family lore, no record of his birth exists) to have been born in 1881 in TN. Searching for a Gore in TN, is just as bad as searching for a "Smith" in the NYC phone books of the day. Having been born in 1881 (TN records from the 1800s have not been helpful), Palmer misses the 1880 census. The 1890 census no longer exists (except for a few unrelated scraps). We think we have him working and living on a farm in Kaufman TX is the 1900 census and he complete disappears after that. Do you think it would be fruitful to look for the descendants of the owners of that farm he worked at in 1900? Thus far, we are working with only two documents that evidence his existence: the 1900 census, and his name on the marriage documents in 1903, from Hunt County TX (Hunt county has no other records - already went down that rabbit hole). I have found records from the 1900-1915 period to be sketchy, and TB deaths were occurring all over - I don't think much documentation took place when a person died lonely and alone in a sanitarium in those times.