When Does "The Kents" #5 (1997) Take Place?
"The Kents" #5 "Brother Versus Brother" Part 1 is a western historical fiction comic-book written by John Ostrander that released October 8th, 1997. So when is "The Kents" #5 set?
It takes place on the fictional DC Comics Universe timeline roughly in the years:
We know this because the real-world American Civil War, which began on April 12th, 1861 AD and ended on May 26th, 1865 AD, is currently ongoing during the story so it must be after April of 1861 AD and before May of 1865 AD.

1860s AD
We know this because the real-world American Civil War, which began on April 12th, 1861 AD and ended on May 26th, 1865 AD, is currently ongoing during the story so it must be after April of 1861 AD and before May of 1865 AD.
More specifically, William Clarke Quantrill (1837-1865) appears so it must be before June of 1865 AD.
Additionally, the book’s opening shows a different perspective on events readers saw .
It is a chronologically early comic in the DC Comics Universe multiverse timeline and can be read at its timeline point after the previous issue, "The Kents" #4 (1997).