He moved to St. Paul, Minnesota in October, 1854.
He was listed as a Democratic party candidate in the 1857 election. (A History of the City of St. Paul to 1875, 1983 edition, by J. Fletcher Williams, p. 382)
His party affiliation when first elected was provided by Minnesota in Three Centuries and this partial quote, "Early in the session Mr. William Sprigg Hall, a prominent Democratic lawyer of St. Paul..." (Sanborn, Gen. John B. "The Work of the Second Legislature, 1859-60." Collections of the Minnesota Historical Society, St. Paul: the Society, 1905, Vol. 10, Part 2, p. 624)
He was the first Judge of the Court of Common Pleas. (Minn. Reports 20, xi)
He platted 160 acres of land on Saint Paul's East Side and is responsible for the "floral" street names in Saint Paul's East Side and North End neighborhoods. Hall st. is named after him, Arundel St., Kent St., and Maryland Ave. are named for his birthplace, and the floral streets were named after a play on his middle name, "being imagined as 'sprigs' of flowering plants." (Collections of the Minnesota Historical Society 17, p. 624-625)
He took a trip to Europe and died in a railroad car on his way home to Minnesota from the East.