This essay studies letters written to McClure's magazine in response to its 1895 publication of a previously unknown photograph of Abraham Lincoln. The letter writers mobilized what I call "image vernaculars," enthymematic arguments grounded in their social knowledge about photography, portraiture, and "scientific" discourses of character such as physiognomy. Armed with these image vernaculars, viewers argued the photograph was evidence of Lincoln's superior moral character, and they used it to elaborate an Anglo-Saxon ideal national type at a time when elites were consumed by fin-de-siècle anxieties about the fate of "American" identity.