William Guyse Hagger (1748–1832), the first of his family to be involved in
the instrument trade, began in business in Newport, R.I., and moved to Boston
after the Revolution. Benjamin King Hagger (1769–1834) moved to Baltimore
around 1816. By 1824, Benj. K. Hagger & Son had a shop at the Sign of Hadley’s
Quadrant that specialized in navigational instruments. In 1830 the Haggers
"opened an extra establishment for the purpose of manufacturing Surveyors
Compasses and Levelling Instruments, which we are now making of a superior
quality, and offer for sale wholesale and retail at very reduced prices."
The wording comes from an advertisement in the Baltimore American.
William G. Hagger (born 1800) and John W. Hagger (1805–1858) took over the
firm in 1834 and began trading as Hagger & Bro.