Whistling Dixie is an idiomatic expression, which is said about people who have unrealistic expectations and overly hopeful fantasies about the future.
You can say someone whistles Dixie if they attempt to engage in conversations that include a faithful idea about forthcoming events.
The expression is often used as “I’m not just whistling Dixie…” in a sentence to reinforce a statement.
The expression refers to the “Dixie song”, which was a marching-song and unofficial anthem for the Confederate troops during the American Civil War.
The song featured a series of wind instruments, and symbolized the continued and relentless fighting for a lost cause. Hence came the expression: Whistling dixie.
Naturally, the expression appeared first in literature during and under the 1860s, when the Civil War was taking place.
However, after the conflict was over, whistling Dixie almost completely disappeared from literature, and only started to gain its popularity back during the 1970s.
Online, the term can be found in the lyrics and as the title of various songs, such as country musician Randy Houser’s track Whistlin’ Dixie, which was released in 2009.