When Does "The Kents" #3 (1997) Take Place?
"The Kents" #3 "Bleeding Kansas" Part 3 is a western comic-book written by John Ostrander that released August 6th, 1997. So when is "The Kents" #3 set?
It takes place on the fictional DC Comics Universe timeline in the year:
We know this because William Clarke Quantrill (1837-1865) appears so it must be before 1865 AD and a major plot point is the tragic Sacking of Lawrence, Kansas, which happened on May 21st, 1856 AD in the real world.

1856 AD
We know this because William Clarke Quantrill (1837-1865) appears so it must be before 1865 AD and a major plot point is the tragic Sacking of Lawrence, Kansas, which happened on May 21st, 1856 AD in the real world.
Furthermore, there is a textbox that includes the sentence: "I think it's safe to say things were not going well for the Kents in the spring of 1856.", referring to the story’s main action. This is followed by three journal entries of Kent family ancestors dated for 1856.
Additionally, the comic opens with a frame prologue, epilogue, and includes four short interludes extending the setting with Pa Kent from issues #1 and #2 which had textboxes telling us it’s "Metropolis, today." So the frame story is set in ‘the present’ of the DC Universe.
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" #2 (1997).