The most common and most likely answer to this crossword clue is the 14 letter word CRACKER-BARREL
I've seen this crossword clue in The Guardian
C
R
A
C
K
E
R
-
B
A
R
R
E
L
More clues leading to the result CRACKER-BARREL
Buddy explains!
The straight part
We know that "Unsophisticated American" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case unsophisticated american = cracker-barrel.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CRACKER-BARREL mean?
CRACKER-BARREL adjective- Folksy; characteristic of simple small-town people.