Leslie,

That helps a lot. I found nothing on your specific ancestor, but I found a lot of activity in and near the corner of southeast Cass, northeast Bates, southwest Johnson, and northwest Henry Counties at that time. I found between June 20 and June 26, 1862 patrols of both the 7th Missouri Cavalry Regiment and the 1st Iowa Cavalry Regiment bringing back large numbers of returned Confederate soldiers and others suspected of being returned Rebels to their bases (Harrisonville, Cass County, for the 7th and Clinton, Henry County, for the 1st) during that period from this specific area. There is no mention in my sources (see below) that these cavalrymen killed anybody who resisted arrest, but such an eventuality is highly likely. There were earlier reports of lots of returned Rebel soldiers in this region and the Federal cavalry was tasked to round up as many of them as they could. You should check online with the Missouri State Archives at http://www.sos.mo.gov/archives/soldiers just to be sure there is no record of Benjamin F. Simpson or B. F. Simpson from this area in either army, particularly the Confederate side.

I don't recall from my reading that the 7th Missouri Cavalry was prone to shoot prisoners or commit many other depredations (as some Union units were known to do), and the behavior of the troopers of the 1st Iowa Cavalry was considered exemplary. However, in this kind of brush war anything is possible, and one side's necessary killing is the other side's "bushwhacking," if you follow my drift. Someone called such uncertainties the "fog of war," which fails to satisfy our thirst to learn more about how our forefathers met their deaths. If your man ran when these troopers rode up to him, they were prone to take that as an admission of guilt of some kind and shoot him down. Sadly, this was the custom in west-central Missouri during the summer of 1862.

My sources for what I found in this area at this time include:
--Broadfoot Publ. Co., "Supplement to the 'O.R.'", part 2, vol. 35 for 7th MO Cav, p. 373, publ. about 15 years ago and this 100 volume set is in large libraries;
--Joanne Chiles Eakin, "Union Military Post Returns," Independence, MO: publ. by author, 1995, pp. 78-80, 86-7.

Just to make things confusing for you, I found on 26 June 1862 at Chapel Hill in southwest Lafayette County a patrol of 2nd Battalion Cavalry Missouri State Militia captured a "Captain Simpson of the Rebel army." These troopers brought in the captain and he was soon after sent for safekeeping to Fort Leavenworth, Kansas, not far away. I failed to find anymore about this Captain Simpson, and, since he was captured about two counties north of where your man was killed, I don't know if this helps at all. My source for this is the Broadfoot set cited above, but in volume 34, 2nd Bn Cav MSM, p. 632.

Frankly, I was hoping to be able to do more for you than this. I commend you to the Cass County Public Library, 400 East Mechanic, Harrisonville, MO 64701 for their historical archives. The Cass County Historical Society meets there, and they may be able to look in their resources for traces of your Mr. Simpson's life and death from local records. Those are usually more help in cases such as these.

I wish you good hunting.

Bruce Nichols