This legend will probably sound familiar to a number of people whose family research includes Civil War-era ancestors: Two of the Floyd brothers fought in the Civil War, one on each side, and after the war they never spoke to one another again, even though they farmed side by side on neighboring farms. This is the same story that numerous Floyd and Moore family cousins have heard many times. The version I actually remember hearing from my mother involved "two of your great-grandfathers." Of course, I was only about 5 or 6 when I heard it, so it may be my memory that is at fault.
One of my goals in doing family research, ever since I started about three years ago, has been to look into various family legends. I did not expect most of them to be absolutely true, but I thought there might be an element of truth in at least a few of them. I realized that this particular legend fit one of the common myths found among family lore, so I did not have high expectations of confirming the legend. What I have been able to find out about the Floyd brothers so far neither confirms nor refutes the legend, but it does make it appear unlikely that whatever feud or ill feelings that may have existed between any pair of the brothers did not fit the precise scenario described in the legend. At this point, there is insufficient information on the lives and fates of some of the brothers to come to a definite conclusion.
The Floyd (and Moore) cousins that I know are all descended from George Floyd's son Charles Augustus Floyd, as am I. We all assume that he is one of the brothers involved, and he did fight in the Civil War. If we assume the other brother involved also fought in the war, that would mean it had to have been either David or Henry Oscar; Caswell and Alford were too young. The problem is that neither I nor other family researchers have been able to find any record of Civil War service for David or Oscar, either in Confederate units or Union units. That does not mean that they did not serve; it just means that we have been unable to find a record so far. The one mention of Oscar during that time frame indicates that he died in Scott County, Illinois in the spring of 1862. If this is true, this may have something to do with the idea that one brother fought for the North. However, this also indicates that he died during the war, so there could have been no question of a feud after the war.
David Floyd, on the other hand, apparently survived the war, as in 1867 he is listed as a witness to his brother Charles' wedding and receives 70 acres in a partition of his father's land in that same year. By 1870, however, he does not appear on the census and his wife has remarried, so some time in between he must have died. If he did fight for the Union, perhaps there is a grain of truth in the story. Or perhaps he did not fight at all, and was resented by his other brothers. However, he would seem to have been on good terms with Charles, since he was a witness at his wedding.
Any other scenario would have to involve either Caswell or Alford, but it could not have both brothers having fought in the war. I would rule Alford out because he and Charles were apparently involved in business deals together in later years. Some time after the war Caswell sold his share of George's land to Charles, so that would seem to rule him out as well. However, Charles lost a great deal of land and money when he could not make the payment for Caswell's land and lost a huge area of land he had pledged as security. Perhaps this led to some sort of ill feelings, and there have always been stories of scraps between Charles' sons and Caswell's sons. However, Caswell no longer lived next to George.
Ultimately getting closer to any resolution of this mystery will require sorting out the Civil War service (or lack of service) of David and Oscar and possibly finding additional evidence of relations among the surviving brothers after the war. If I assume that there is a bare minimum of truth in the legend, the elements that went into its formation may have been the location of Oscar's death during the war and the fighting between Charles' and Caswell's sons.