Complex sentence: The development of the detachable collar by Hannah Lord Montague in 1827 had given the city the product that still lends it its "Collar City" nickname, and plants were built to manufacture them commercially, as well as cuffs and other textile products.
Split into simpler sentences: The development of the detachable collar by Hannah Lord Montague in 1827 had given the city the product that still lends it its "Collar City" nickname. Plants were built to manufacture them commercially, as well as cuffs and other textile products.