Official Register of the United States, containing a list of the officers and employes in the civil, military, and naval service on the first of July, 1891; together with a list of vessels belonging to the United States. Volume II. The Post Office Department and the postal service.
Publication: Serial Set Vol. No.2986;
Report: H.Misc.Doc. 50 pt. 2; lists Theophile B. Prew as postmaster, Val Verde, Texas, Comstock.
There is a family tree at Ancestry.com that states he died in 1930 at St. Paul, Minnesota.