Sprague arrived at Naumkeag (Salem) in mid-July 1629 with his brothers Ralph and Richard.
They were employed by Governor Endecott to explore and take possession of the country westward.
They explored the land to (present day) Charlestown, Massachusetts, between the Mystic and Charles rivers, where they made peace with the local Indians.
On February 10, 1634, the order creating a Board of Selectmen was passed, and Richard and William Sprague signed it.
Sprague’s will names his wife, Millicent (Eames), and children, Anthony, Samuel, William, Joan, Jonathan, Persis, Johanna and Mary.