I believe it is yet to be established that the 48th was Carlton's Regiment

But, if it was, then there is this:

George Washington CSR-formerly 10th Mo Cav MSG;
6/9/64 Paid through 5/31/64 as clerk -pay roll of one man detailed with George Johnson, Maj & Chief Ins…
1st Lt & Adjt Carlton’s Ark Cav Regt assigned 8/1/64,
10/25/64 captured in Kansas