This is Francis Bicknell Carpenter's famous depiction of Lincoln reading his draft of the preliminary Emancipation Proclamation, July 22, 1862. Secretary of the Treasury Salmon P. Chase, standing on the far left, recalled Lincoln advising before he began” “I have got you together to hear what I have written down. I do not wish your advice about the main matter, for that, I have determined for myself. . . I must do the best I can and bear the responsibility of taking the course which I feel I ought to take.”
A. H. Ritchie's engraving of the painting is viewable at http://memory.loc.gov/cgi-bin/query/r?ammem/presp:@field(NUMBER+@band(cph+3a05802. For the artist's perception of the event, as gleaned from his stay at the White House, painting after the fact, see Francis Bicknell Carpenter's The Inner Life of Abraham Lincoln, Six Months at the White House (1867). A thoughtful introduction to the painting is offered by an instructional exercise prepared for the White House Historical Association, accessible at http://www.whitehousehistory.org/04/subs/images_subs/primary_1863.pdf . And the painting and derivative art work is discussed in detail in The Lincoln Image: Abraham Lincoln and the Popular Print (Harold Holzer, Gabor S. Boritt, and Mark E. Neely, Jr., 1984). Some discussion of the painting is also offered in The Battlefront: Newsletter of the Onondaga County Civil War Round Table 11, no. 5 (January 2005) at http://library.morrisville.edu/local_history/sites/cwrt/newsletter-Jan-2005.pdf .