In the early 1900s, the phrase was: “You can take a boy out of the country, but you can’t take the country out of the boy.”
 
By 1950, the phrase was adapted to Texas: “You can take a boy out of Texas, but you can’t take Texas out of the boy.” A similar saying is “You can take the girl out of the honky tonk, but you can’t take the honky tonk out of the girl.”
   
   
Google Books
Hunting the Tango
a novel by Burr S. Stottle
Kansas City, MO: Burton Publishing Company
1916
Pg. 10:
“You know the old saying, Hazel, that you can take a man out of the country, but you can’t take the country out of a man, and I guess that is true of your old uncle.”
 
Google Books
Second Growth
a novel by Arthur Pound
New York: Reynal & Hitchcock
1935
Pg. 104:
“You can take a boy out of the country,” he observed, “easier than you can take the country out of a boy.”
 
Google Books
Ink On My Hands
by Clayton Rand
New York: Carrick & Evans, Inc.
1940
Pg. 136:
“Well, Pat, you can take the boy out of the country, but you can’t take the country out of the boy.”
     
Wikipedia: Salem (cigarette)
Salem is brand of cigarettes introduced in 1956 by the R.J. Reynolds Tobacco Company as the first filter-tipped menthol cigarette. Its name (along with that of the Winston brand) derives from Winston-Salem, North Carolina, the city where RJR was founded and headquartered.
 
In the late 1960s, the brand’s slogan (sung to music in television and radio commercials prior to their prohibition on January 1, 1971) was “You can take Salem out of the country, but…you can’t take the country out of Salem.”
 
28 April 1950, Los Angeles (CA) Times:
You can take a man out of Texas, but you can’t take Texas out of the man.
   
19 July 1950, Winnipeg Free Press, pg. 10, col. 2:
There was an old saying: you could take a boy out of Texas, but you couldn’t take Texas out of the boy.
     
23 August 1951, Kerrville (TX) Times, pg. 2, col. 5:
Cpl. Joe Shellhase believes the old saying that you can take a boy out of Texas but you can’t take Texas out of the boy.
     
5 December 1974, Pasadena (CA) Star-News, pg. D6, col. 1:
His life, in fact, is a testament to the maxim that “you can take a man out of Texas, but you can’t take the Texas out of the man.”
 
Google Books
On the Road With Jesus
by W. D. Cravenor
Xulon Press
2005
Pg. 99:
Among Texans, it is often said, “you can take the boy out of Texas, but you can’t take Texas out of the boy.”