In 1852, the Fortenbach family emigrated from Germany to the United States and settled in Carlstadt, New Jersey. They began their entrepreneurial journey in brass manufacturing, producing items such as brass belt plates and bayonets for the Federal Army during the Civil War. This venture proved successful and helped establish the family as skilled industrialists.

Following the war, the Fortenbachs shifted their focus to the growing watch case industry. Recognizing the demand for silver watch cases, they specialized in their production, and their business flourished. By the 1870s, their facility, located at the corner of First and Second Streets in Carlstadt, underwent several expansions to accommodate the increased demand. By 1876, the company was operating under the name "Fortenbach & Sons" and was well-regarded in the business of silver watch cases.

In 1861, the Fortenbach family partnered with Joseph Fahys, who had gained experience in watch case manufacturing in New York. Their collaboration helped modernize the factory’s operations and further expanded its capabilities. Fahys' involvement brought new opportunities to the business, as he contributed his expertise in scaling production and refining processes.

In 1876, Joseph Fahys bought out the Fortenbach family’s interests, taking full control of the Carlstadt factory. The facility continued to operate under Fahys’ management for several years before he relocated the equipment and operations to Sag Harbor, Long Island, marking the end of the Fortenbach family's direct role in the factory. Despite this transition, the Fortenbachs’ early contributions to the watch case industry left a lasting impact.

Over time, the Carlstadt facility found new uses. It briefly operated as a cooperative watch case factory before being converted into a hat factory. Meanwhile, members of the Fortenbach family continued to work in the watch case industry. In 1898, Henry Fortenbach, one of Joseph Fortenbach's sons, was hired by the Crescent Watch Case Company in Roseville, New Jersey, carrying on the family’s legacy in the trade.