DescriptionCHARLES KELLER (American 1914-2006) "Concrete Foundation- 6th Avenue Subway" Lithograph. Sight: 14 x 18 inches; frame 21 x 24 inches. Signed in pencil lower right: Charles Keller. Inscribed in pencil bottom center margin: For Marge and Hank. Titled lower left: Concrete Foundation - 6th Avenue Subway. Notes: Part of a series of lithographs 1937/1941 of workers constructing the Sixth Avenue Subway.