printing business to them (which then became known as Crocker & Brewster) and focused his activities on the bookshop. In 1825, he withdrew from the day-to-day operations of the business, but would retain a financial stake until 1840. He continued to maintain a personal interest in the business until his death. The business was a significant financial success, and made Armstrong fairly wealthy. Church and politics Armstrong was a member of the Old South Church. He served on its vestry (including as its secretary), and was chosen deacon in 1829. When the church was formally incorporated in 1844 Armstrong was named as one of its proprietors. In 1816 Armstrong discovered the original manuscript of the third volume of colonial Governor John Winthrop's History of New England in the church's tower; the volume was presented to the Massachusetts Historical Society. He was also in part responsible for the church's loss of a perfect specimen of the 17th century Bay Psalm Book, one of five that had been willed to the church by Thomas Prince, an early minister of the congregation. Writer Robert Wallace suggests that Armstrong's trade of two copies of the book in exchange for offers by the recipients, George Livermore and Edward Crowninshield, to rebind the other copies was naive, and was essentially a scam by Livermore and Crowninshield (both knowledgeable in the rare book trade) to acquire the valuable books for a bargain price. Armstrong was involved in civic affairs as early as 1812, when he served in a Boston militia company during the War of 1812. He entered state politics as a representative in Massachusetts General Court (state legislature), serving in that body from 1822–1823 and in 1828–1829. From 1828 to 1830 he served on Boston's board of aldermen. In 1833 Armstrong was offered the nomination for lieutenant governor by the state Anti-Masonic Party. Since he refused to subscribe to their view that Freemasonry should be abolished, he rejected the offer. He was, however, elected lieutenant governor on the Whig ticket, serving first under Levi Lincoln, Jr. and then John Davis. Whig newspapers used his working-class roots to appeal to members of the Working Men's Party, a third party founded on labor issues, describing him in the 1834 campaign as "a Mechanic and Workingman". When Davis resigned in March 1835 upon his election to the United States Senate, Armstrong served as the Acting Governor until 1836. In