You must be correct as there was not ever to my knowledge a Linn County,
Arkansas. The information did say Arkansas. You say there was county
by that name in Kansas, so that makes more sense.
As far as learning about the 3rd, just read everything you can about what
was going on in the war at that time. Many of those people were so busy just
surviving that it was not written down.
I try to follow the following CSA Unints: 36th Arkansas, the 10th, the 1st Arkansas
Cav.and the 8th Arkansas as I had kin in those units. I also follow any information about
Price's raid north as my ggg uncle rode with him. Out of state, I am interested in the
7th Tenn. Cav. and the 5th Tenn. Inf.
I also just discovered yesterday, the long lost ggg grandfather of my children who was
actually laying in a marked CSA grave in Savannah, Georgia.
My point being is always be on the lookout.
Also, check the Goodspeed of 1889-genealogy book covering the counties that the men
came from- and see if you can pick up some information on those who would have been
with the 3rd. By reading the one covering White County, I found the uncle.
My personal information would be useless to you, but if you stay with the task, it
can be done.
Good luck in your search.