Zion (zĪˈən) [key], city (1990 pop. 19,775), Lake co., extreme NE Ill., on Lake Michigan; inc. 1902. Largely residential, the city has some light industry. Zion was founded in 1901 by John Alexander Dowie, the Scottish founder of the Christian Catholic Church. Until 1935 the city was a communal society with a theocratic government; the church remains an important force there. Of note are the huge Zion Hotel (1902), and Shiloh House (1902), the mansion built for the Dowie family. Illinois Beach State Park is nearby.