"First known portrait of an American interracial family." https://ajoconnell.wordpress.com/2010/11/09/the-drop-sinister/ Title refers to “one-drop rule,” which considered anyone with even partly African American parentage a “negro”. Lincoln's portrait and the pervasive sense of tension among the figures suggest that for this family Lincoln's promise of racial equally has not yet been fulfilled. (http://books0977.tumblr.com/post/151409656067/the-drop-sinister-what-shall-we-do-with-it)