Running for the Republican nomination and ultimately re-election as United States President, incumbent William Howard Taft visited Springfield during the height of a contentious primary campaign waged against his political rival, Theodore Roosevelt, giving a speech at Court Square on April 25, 1912, before a crowd of 20,000.
Taft went on to win the nomination, spurring Roosevelt (who had already served as President for the 7 1/2 years prior to Taft) to form the Progressive Party. The Republican Party thus split resulted in the first election of a Democrat, Woodrow Wilson, to the highest elected office in the land in 20 years.
Photo source: Library of Congress; American Memory Collection; http://memory.loc.gov/cgi-bin/query/r?pp/ils:@filreq(@field(NUMBER+@band(ggbain+11216))+@field(COLLID+ggbain)); Believed taken April 25, 1912 (possible alternate date: 1909).