Full credit to Wikipedia for this:  “The Trianon Ballroom was the name given to a number of ballrooms in cities during America’s big-band era. The first and most prominent Trianon opened in 1922 in Chicago. Designed by theater architects Rapp & Rapp, it was owned and operated by William and Andrew Karzas, who opened the Aragon Ballroom in Chicago four years later. The Trianon’s size, opulence and success led to other ballrooms to be similarly named in identifying with the original. Cleveland, Philadelphia, Seattle, Toledo, and the Los Angeles suburb of South Gate each had a Trianon Ballroom.  The location in Chicago at 6201 Cottage Grove Avenue was the origination point for many live broadcasts on Chicago radio station WGN. It was demolished in 1967.”  Just thought you’d like to know.  The card was mailed by a soldier who did not need a stamp; faint and incomplete postmark.  Grade: 1