text: After leaving this position, a man claimed he was leading an expedition to look for tree-climbing fish.
full_question: After leaving this position, a man claimed he was leading an expedition to look for tree-climbing fish. A man who held this post was mocked with the line "Tony, Tony, where's your pushcart?" and the slur "Bohunk" by corrupt rival William Hale Thompson. Disgruntled office seeker Patrick Prendergast murdered a man holding this position in the 1870s, named Carter Harrison Sr. In 1933, a man holding this position was critically wounded by Giuseppe Zangara in Miami; that man, Anton Cermak, was shot while shaking hands with actual target Franklin Roosevelt. For 10 points, name this political position whose 1893 occupant led his city in hosting the World's Columbian Exposition.
first_sentence: After leaving this position, a man claimed he was leading an expedition to look for tree-climbing fish.
raw_answer: Mayor of Chicago