I searched through the three books I have on Bedford County: 1) "Bedford County Families and History" compiled from Hardesty's Encyclopaedia; 2) "Marriage Bonds of Bedford County 1755-1800" by Dennis and Smith; 3) "Over The Mountain Men Their Early Court Records in Southwest Virginia" by Worrell.
The only references to McKinney I could find were in 1) above.On page 82 there is a reference to NANCY McKINNEY who was married to Joseph Wilkerson of Campbell County,VA, parents of Martha Y Wilkerson. On page 17: "McKINNEY, J.H." is listed as a member of Company G, 34th Virginia Infantry.And on page 22 "McKENNEY JOHN H." (their spelling)was:"enlisted April 1862. Captured April 1865. Held at Elmira."
I am sorry that those were the only references I could find in the materials that I have on hand.The Smith and Dennis "Marriage Bonds" book seems to have only the wife's names listed in the Index.If you have Mary McKinney's maiden name I can look for that.
Your Robert Beard is not a part of my family line.There were two John and Elizabeth Beards in VA at the same time. Your Ropbert's group were in Augusta and the second were in Bedford/Cambell.The Augusta Beards seem to have mostly moved south and then west, while the Bedford Beards moved north and west into WV and OH. I have not been able to establish any connection to the two families.
Sorry that I could not be of more help to you.Good luck in your research.mike beard