Jamaica is 18 times larger than Chicago.
Area: 10,991 km2 World Factbook
Population: 2,930,050 (July 2014) World Factbook
Jamaica is an island country situated in the Caribbean Sea, comprising the third-largest island of the Greater Antilles. Wikipedia
Area: 608 km2 calculated
Chicago is the third most populous city in the United States, after New York City and Los Angeles. With 2.7 million residents, it is the most populous city in both the U.S. state of Illinois and the American Midwest. Wikipedia