Richard:
I don't know what the relationship was between the two Abshires in the 42nd Va. However, Jacob W. Abshire served only briefly. He enlisted in K/42Va on 23 August 1863, deserted 17 September 1863 and was carried on the unit rolls through 31 Pctober 1864 as a deserter. Marcus W. Abshire enlisted in K/42Va in July 1861; was a POW for a while in 1862 until exchanged; was wounded at Chancellorsville and Payne's Farm in 1863; and wounded again, possibly at Cedar Creek, in 1864. He was furloughed from Charlottesville hospital on 15 December 1864 and there his record ends. What can you do to fill in the gaps?