License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Thomas Sully. Horseman Addressing Two Women; Palette, Brushes in Artist's Hands, Picture and Easel Beyond; Putto Blowing Clarion (from Sketchbook), 1810–20. The Metropolitan Museum of Art.