Hi Kathleen -
dunno if your Vaughn ancestor(s) had any relatives in the 17th or 11th/17th Ark. Infantry, but here are some names for your inspection:
Vaughan, Benjamin ----Co. H 17th Ark. Inf. Sgt/Sgt
Vaughn, Daniel ----Co. G 17th Ark. Inf. Pvt/Pvt
Vaughn, William F. ----Co. C, D 11th/17th Ark. Inf. Pvt/Pvt
More info can be perused at the URL given below.