Oliver H. P. Carey is listed as a lieutenant colonel of a Union volunteer regiment during the American Civil War. Extensive searching of Wikipedia, Find A Grave, state adjutant-general rosters, and regimental histories under multiple name variants (full name, initials, likely home states) turned up no record that could be confidently matched to this specific individual. He appears to be a genuinely obscure regimental officer whose service, like that of many volunteer field officers, survives only in local or unit-level records not reachable through general search.