Conflicting advice, to free all slaves, or not free them at all, was presented to Lincoln in public and private. Thomas Nast, a cartoon artist during the Civil War and the late 1800s considered "Father of the American Cartoon", composed many works including a two-sided spread that showed the transition from slavery into civilization after President Lincoln signed the Proclamation. Nast believed in equal opportunity and equality for all people, including enslaved Africans or free blacks. A mass rally in Chicago on September 7, 1862, demanded an immediate and universal emancipation of slaves. A delegation headed by William W. Patton met the president at the White House on September 13. Lincoln had declared in peacetime that he had no constitutional authority to free the slaves. Even used as a war power, emancipation was a risky political act. Public opinion as a whole was against it. There would be strong opposition among Copperhead Democrats and an uncertain reaction from loyal border states. Delaware and Maryland already had a high percentage of free blacks: 91.2% and 49.7%, respectively, in 1860.