Both Joan Fontaine and Eva Marie Saint were tested for the role of Marjorie. George Sidney preferred the younger Kim Novak.
The Central Park Casino was portrayed in the movie by the famed Tavern on the Green, also located in Central Park, since by the time of filming in the mid-50s the Casino was long gone.
The characters of "Mr. and Mrs. Sherman Wadsworth" are fictionalized versions of the real-life Mr. and Mrs. W. Averall Harriman, Marjorie Duchin's uncle and aunt. Averell Harriman was the heir to his father's, E.H. Harriman, railroad fortune, and devoted most of his life to public service, including stints as US ambassador to the Soviet Union and to the Paris Peace talks during the Vietnam War. At the time "The Eddy Duchin Story" was released (1956), Harriman was in the midst of his term (1955-1959) as Governor of New York, and was a candidate for the Democratic presidential nomination that year.