“My fellow Americans” is often how a politician (such as a president or a senator) addresses the people of the United States. “My fellow Americans” has been cited in print since at least 1766. President Dwight D. Eisenhower (1890-1969) used “My fellows Americans” in a “report to the nation” radio address from the White House in 1953 and in a State of the Union address in January 1954.
 
   
Wiktionary: my fellow Americans
Noun
my fellow Americans
1. (US) Used to establish credibility and connection with an audience of Americans, used mostly in speeches by US politicians.
 
26 May 1766, Newport (RI) Mercury, pg. 2, col. 1:
From the PENNSYLVANIA GAZETTE, May 8, 1766.
(...)
BUT, my Fellow Americans, excuse me.
 
17 August 1774, Pennsylvania Journal, or Weekly Advertiser (Philadelphia, PA), pg. 5, col. 1:
But I would not offer such an affront to your understandings, my fellow Americans, as to suppose you are yet to be informed, ...
 
27 October 1900, The Evening Tribune (San Diego, CA), “The Roosevelt Rally” (AP), pg. 6, col. 2:
Another ovation followed as the governor raised his hand to command attention. He began address with the words: “My fellow Americans.”
 
25 May 1941, Boston (MA) Herald, “Kennedy Sees Aid Failure,” pg. 1, col. 8:
“We cannot, my fellow Americans, divert the tides of the mighty revolution now sweeping Asia and Europe.”
(Joseph P. Kennedy, former U.S. Ambassador to Great Britain.—ed.)
 
7 August 1953, Dallas (TX) Morning News, “Eisenhower Text,” pt. 1, pg. 6, col. 1:
WASHINGTON (AP)—The text of President Eisenhower’s “report to the nation” by radio from the White House Thursday night follows:
 
My Fellow Americans: ...
 
5 January 1954, Boston (MA) Herald, “Eisenhower’s Report to the Nation,” pg. 4, col. 3:
WASHINGTON, Jan. 4 (AP)—Following is the text of President Eisenhower’s broadcast report to the people tonight:
 
My fellow Americans: ...
   
Wikiquote: Patriotism
And so, my fellow Americans: ask not what your country can do for you — ask what you can do for your country.
My fellow citizens of the world: ask not what America will do for you, but what together we can do for the freedom of man.
. John F. Kennedy, Inaugural Address, (20 January 1961)
 
9 January 1964, Aberdeen (SD) American-News, “Goldwater Hits At LBJ ‘Hate Theme’” (AP), pg. 1, col. 7:
In his State of the Union message, Johnson said:
 
“My fellow Americans: In these last seven weeks we have learned anew that nothing is so enduring as faith and nothing is so degrading as hate.”
   
OCLC WorldCat record
My fellow Americans.
Author: Malcolm Boyd
Publisher: New York, Holt, Rinehart and Winston [1970]
Edition/Format:   Print book : English : [1st ed. ]
 
OCLC WorldCat record
My fellow Americans : patriotic cartoons
Author: Ron Cobb
Publisher: Los Angeles : Price/Stern/Sloan-Sawyer Press, 1971, ©1970.
Edition/Format:   Print book : Fiction : English
 
OCLC WorldCat record
“My fellow Americans, there are those who would divide us—can you hear me all right?—”
Author: Herbert Block
Publisher: 4/26/1972.
Edition/Format:   Image : Graphic : English
Publication: Herbert L. Block collection (Library of Congress)
 
OCLC WorldCat record
“My fellow Americans, I, too, have a dream. Therefore, I’d like to make a very special announcement”
Author: Seymour Joseph
Publisher: 1988 Mar. 10.
Edition/Format:   Image : Graphic : Original artwork : English
Publication: Ben and Beatrice Goldstein Foundation collection
Database: WorldCat
Summary:
Drawing shows Ronald Reagan sitting at a desk announcing to the American public that he has a dream; on the wall behind him is a map of United States labeled, “United States Incorporated.” Television news cameras are visible in the foreground.
 
Wikipedia: My Fellow Americans
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.
     
PBS NewsHour
Who coined ‘my fellow Americans’ and other State of the Union trivia
BY RACHEL WELLFORD January 11, 2016 at 4:54 PM EST
(...)
. While John F. Kennedy coined the term “My fellow Americans,” Lyndon Johnson was the first president to add the words to his State of the Union introduction.