The Republican abolitionist played a key role in Abraham Lincoln's battle against slavery, but is absent from Steven Spielberg's film. Michael Shank, a professor at George Mason University, writes: "It is ironic, in fact, that 'Lincoln' opens with a close-up of black soldiers in conversation with the president. It was Frederick Douglass who not only recruited black soldiers for the Union army, but he also ardently advocated to ensure these very black soldiers had equal pay, were treated equally, especially if captured, and received the same promotions as white soldiers. Frederick Douglass made this film scene feasible. He found it absolutely inexcusable that black soldiers who served in the Army during the Civil War – totaling nearly 200,000 by the end – were being treated as second-class citizens, despite dedicating and ultimately sacrificing their lives for the country."