The History Channel had a mini-series in the feud a few years ago that was excellent. It had an all-star cast with Kevin Costner, Bill Paxton, Tom Berlinger and Powers Booth, to name a few. It was very good and pretty historically accurate.accurate.
That is probably the one I saw. It is on Amazon Prime right now to own the first part of the series it is reduced to 4.99 but there are three parts and the other parts are 9.99 each. Called Hatfields & McCoys.