In 1867 he was elected to the Assembly district which encompassed both Marathon and Wood Counties, succeeding fellow Democrat George Hiles; he was assigned to the standing committees on school and university lands, and on enrolled bills.

In 1873 he was again elected to the Assembly for a one-year term (the district now consisted solely of Marathon County) to succeed his banking partner Daniel L. Plumer, this time as a "Liberal Democrat".

In 1874 he was elected to the State Senate from the 21st District (Marathon, Oconto, Shawano and Waupaca counties and parts of Outagamie County) as a Liberal Democratic/Reform candidate, with 4693 votes to 3968 for Stalwart Republican Elisha L. Bump, for a two-year term; he was assigned to the committees on the judiciary and on federal relations in the first year, moving in the next session from federal relations to the committees on banks and banking, and on privileges and elections.

in January 1897 he was the Democratic candidate for United States Senate; he was defeated by John Coit Spooner, the Republican candidate; he was also opposed by Gold Democrats such as Jesse Clason (who voted for Spooner) and Albert Solliday, who cast a protest vote for William Freeman Vilas.

[4] In 1903, Scofield appointed Silverthorn to a Wisconsin Circuit Court seat; he was re-elected in 1904, defeating old rival Elisha Bump.