Information about the family background and early life of Arthur Moore (1666?-1730) in Ireland is sketchy, although there is some correspondence from Irish relatives in this collection. The collection at Spencer largely documents the activities in England of Arthur Moore and his immediate family and their acquaintances. He was employed in London as early as 1681 at the Alnage (or Aulnage) Office that oversaw the quality control of woolen cloth production. By 1686 he was a co-agent for George Monck, 2nd Duke of Albemarle (1653-1688), who had invested in a successful expedition to retrieve treasure from a sunken Spanish galleon.

After the Duke died suddenly in 1688, Moore served as agent for the Duchy of Albemarle estates until 1692, when the Duchess remarried and her new husband, taking advantage of her insanity, assumed control. For most of the period from 1695 to 1722, Arthur Moore represented the borough of Great Grimsby, Lincolnshire in Parliament. Personal involvement in various ventures included the South Sea Company, the Convex Lights Company, the Royal Fishery, the Royal African Company, and the Royal Company of Mines.

After 1702, Moore was appointed to various government positions, including manager of the East India Company, Comptroller of Army Accounts, Commissioner of Trade and Plantations, and Director of the South Sea Company. However, he came under suspicion of profiteering during negotiations for the Treaty of Utrecht in 1713. In 1722 he lost his seat in Parliament, afterward retiring to Fetcham Park, the estate he had purchased in 1705 near Leatherhead in Surrey. He had also invested in the nearby manor of Polesden. Costly lawsuits and estate maintenance ate up his fortune, leaving debts to settle after he died in 1730 and a much diminished inheritance for his widow and sons.

In 1691 in London, Arthur Moore had married Susanna Browne (1673-1694), daughter of physician and traveler Edward Browne and granddaughter of physician Sir Thomas Browne. Her death followed those of their two infant daughters. Arthur Moore’s second marriage in 1696, at Westminster Abbey, was to Theophila (1676?-1739), daughter of William Smythe of the Inner Temple and Lady Elizabeth, eldest daughter of George, Earl of Berkeley. Their six children included three sons (in order of birth): William (1697?-1746), Arthur (1699?-1734), and James (1702-1734).

Arthur Moore’s brother, Colonel Thomas Moore (1668?-1735), had commanded one of Queen Anne’s regiments of foot before becoming Paymaster to her land forces abroad. In 1729, having profited from a South Sea Company investment, he bought the Polesden estate from Arthur Moore, who was in financial difficulty.

Arthur Moore’s middle son, Arthur, or “Atty,” married Elizabeth Ormond. He died in 1734, his early death having been hastened by his insalubrious way of life. James, or “Jemmy," the youngest of Arthur Moore’s sons, outlived his brother by only a few months. Well before receiving a BA degree from Oxford University in 1722, James’s profligate lifestyle had alienated his father. He remained close to his maternal grandfather William Smythe, who arranged his appointment as Receiver and Paymaster of the Band of Gentleman-Pensioners in 1718. The same grandfather’s bequest to James in 1720 required him to change his surname to Smythe (recognized by Act of Parliament in 1728). After running through his inheritance, James Moore Smythe sought to earn money as a playwright. His play The Rival Modes (1727) was modestly profitable, but a critical tongue-lashing for plagiarism by Alexander Pope ruined his reputation. Smythe died impoverished and unmarried in Middlesex in 1734. William, or “Billy,” Arthur Moore’s eldest son, outlived his brothers and his uncle Thomas. In 1730 he succeeded his father at Fetcham Park in Surrey but had to sell it in 1735 to pay his father’s debts. In that same year his uncle died, and William succeeded him at Polesden Lacey, his estate in Surrey. William Moore was returned by his friend, Francis North, 1st Earl of Guilford, in November 1740 as a member of Parliament for Banbury, a seat that he held until his death in 1746. When William Moore visited North’s estate, Wroxton Abbey, in Oxfordshire, he was a favorite of his friend’s young sons, including Frederick (1732-1792), the future Prime Minister of Great Britain. William Moore bequeathed his estates to Frederick North, but the necessity of selling them to pay debts is documented in the correspondence of Francis North as Moore’s executor.