Is your Sylvester V. Pratt the same man who married Margaret T. "Maggie" Currie on 10 Dec 1878 near Crescent? He was the son of Charles F. Pratt for whom there is an 1891 biography at the USGenWeb site for Pottawattamie County. S.V. Pratt and wife Maggie also appear in the 1880 census for Pott. Co. Mona