According to the source information given in THE HISTORY OF BENTON COUNTY (see my reply to Terry Justice), the unit was recruited in Benton and Hickory Counties on APRIL 1, 1862.
John R. Foster was commissioned captain February 28, 1864.
Thanks for the interesting info. I am in awe of you guys who know so much more about all this stuff than I do! I have LOTS of questions I'd like to ask, but don't want to bore all of you!