J. G. Tanner is identified by the inscription on the National Gallery's painting Engagement Between the "Monitor" and "Merrimac" (1953.5.36). No biographical information or additional works by J. G. Tanner have been found, but it is known that the painting is based on a color lithograph issued in 1891. Tanner was active, therefore, in that year or later. [This is an edited version of the artist's biography published in the NGA Systematic Catalogue]
Chotner, Deborah, with contributions by Julie Aronson, Sarah D. Cash, and Laurie Weitzenkorn. American Naive Paintings. The Collections of the National Gallery of Art Systematic Catalogue. Washington, D.C., 1992: 381-382.