Arkansas had nothing to gain. Arkansas was in prosperous times then. Very few people in Arkansas even owned slaves. They did hold meetings prior which leaned on the confederacy side if war should move their way.
But, I think largely many men join the union to survive. Especially if they were in Northern areas Of Arkansas by 1963 when the union pretty much pushed out the Confederacy. But, what I've read is the Arkansas men were looked down on by the union soldiers with distrust. I read that they were not given firearms. They pretty much did the labor jobs of hauling, tending, cleaning, feeding, etc.. I wonder about this. Does anybody have any records of the Arkansas unionists that held firearms and used them against the Confederacy, or were they merely attached to the Union regiments as slave laborers?