Splitdorf-Bethlehem Electrical Co. issued to Thomas A. Edison Inc. with printed signature of Charels Edison and Harry F. Miller - 1929 dated Stock Certificate (Uncanceled)

The Splitdorf-Bethlehem Electrical Company, established in 1924 through the merger of the Splitdorf Electrical Company and the Bethlehem Spark Plug Company, emerged as a prominent American industrial entity. Founded in the mid-19th century, Splitdorf had established a formidable reputation as a pioneer in ignition systems, particularly renowned for its high-tension magnetos utilized in early automobiles, motorcycles, and aircraft during World War I. By aligning with Bethlehem, a specialist in porcelain-insulated spark plugs, the newly unified Newark-based corporation sought to establish dominance in the rapidly expanding automotive and radio markets. This consolidation enabled the firm to provide a comprehensive range of electrical components, encompassing generators, starters, and the highly performance-oriented “Green Jacket” spark plugs.

Despite its robust engineering foundation, the company’s trajectory was shaped by the fluctuating technological shifts of the late 1920s. As the automotive industry transitioned towards battery-based ignition systems and abandoned magnetos, Splitdorf-Bethlehem significantly redirected its focus towards the burgeoning radio manufacturing sector, producing popular vacuum tube receivers and speakers. However, the company encountered challenges in patent litigation and the intense competition prevalent during the pre-Depression era. In 1929, the enterprise was largely absorbed by the Edison-Splitdorf Corporation, a venture supported by Thomas Edison’s interests, which aimed to integrate Splitdorf’s manufacturing capabilities into the broader Edison industrial empire. While the original name eventually faded from the forefront of American industry, the company continues to hold a significant position in the annals of early 20th-century electrical engineering.