Wiktionary
n. (context US English) (non-gloss definition: Used to establish credibility and connection with an audience of Americans, used mostly in speeches by US politicians).
Wikipedia
My Fellow Americans is a 1996 American comedy film starring Jack Lemmon and James Garner as feuding ex-presidents. Dan Aykroyd, Lauren Bacall, Esther Rolle, John Heard, Wilford Brimley, Bradley Whitford and Jeff Yagher are also in the cast. It is named for the traditional opening of Presidential addresses to the American people.
Lemmon's perennial collaborator, Walter Matthau, was slated to costar. Health problems kept him from appearing so Garner was chosen to star opposite Lemmon for their first project together. The film was unofficially called "Grumpy Old Presidents" by those on the set.
Usage examples of "my fellow americans".
I ask you tonight, my fellow Americans, for that commitment, for that willingness.
Like millions of my fellow Americans, I can see no justification at this point in time for trusting the Russians—.