Where did Chicago’s nickname “The Windy City” come from?

Dear Tom,
I have heard several explanations for Chicago’s nickname “The Windy City,” but they are all different. What is the real explanation?
— Jimmy Coltier, Chicago
Dear Jimmy,
Chicago is, indeed, a rather windy city, but it certainly isn’t the windiest. With an average wind speed of 10.3 mph, Chicago ranks 12th windiest among the nation’s major cities. Boston is windiest, with an average of 12.4 mph.
A likely source of the nickname is political. Frequent political conventions were held in Chicago in the latter portion of the 1800s, and long-winded politicians were often described as “windy.”
Rivalry with Cincinnati is also a possible source of the nickname. Chicago surpassed Cincinnati in the 1860s in meatpacking. The Cincinnati press and Chicago Tribune first used the “Windy City” term in 1876.