The career of Jonathan Belcher as Governor of Massachusetts and New Hampshire (1729-1741), and of New Jersey (1746-1757), spanned an era sometimes referred to as the prelude to the American Revolution. Eleven of Belcher's letter-books include letters and materials pertaining to such people as Josiah Quincy, Lord Townsend, Hugh Walpole, and members of the Lords of Admiralty, Lords of Trade, Massachusetts Assembly, and New Hampshire Assembly.

Unique insight into New England politics and political tumult during this important period in American history is provided for Revolutionary War scholars and students.