Harper's Weekly, and Nast, played an important role in the election of Abraham Lincoln in 1864, and Ulysses S. Grant in 1868 and 1872. In September 1864, when Lincoln was running for re-election against Democratic candidate George B. McClellan, who positioned himself as the "peace candidate", Harper's Weekly published Nast's cartoon "Compromise with the South - Dedicated to the Chicago Convention", which criticized McClellan's peace platform as pro-South. Millions of copies were made and distributed nationwide, and Nast was later credited with aiding Lincoln's campaign in a critical moment. Nast played important role during the presidential election in 1868, and Ulysses S. Grant attributed his victory to "the sword of Sheridan and the pencil of Thomas Nast." In the 1872 presidential campaign, Nast's ridicule of Horace Greeley's candidacy was especially merciless. After Grant's victory in 1872, Mark Twain wrote the Artist a letter saying: "Nast, you more than any other man have won a prodigious victory for Grant—I mean, rather, for Civilization and Progress." Nast became a close friend of President Grant and the two families shared regular dinners until Grant's death in 1885.