In 1935 – the height of the great depression – a young engineer by the name of Ralph Allison founded ADC in the basement of his south Minneapolis home, inventing ADC's very first product, the audiometer, an electronic device designed to test hearing.

Two years later, fellow engineer Walt Lehnert joined Allison, and together they diversified the company's product line to include amplifiers and transformers for the broadcast industry. By 1942, the company had designed a sophisticated audio system for the University of Minnesota, and the resulting jacks, plugs, patch cords and jackfields became the cornerstones for ADC's later entry into telecommunications.

In 1949, ADC sold its audiometer product line and Ralph Allison left ADC to form a new company in California. ADC diversified and focused its efforts in the area of transformers and filters for power lines, military electronics, telephone jacks and plugs. And in 1961, ADC merged with Magnetic Controls Company, a manufacturer of power supplies and magnetic amplifiers with strong ties to the U.S. space program.

The resulting company, ADC Magnetic Controls, had a decade of mixed success. Although transformer sales boomed during the 1960s, other new product initiatives failed to materialize. Perhaps the most significant product innovation during this period was the bantam jack, a miniaturized component that eventually became the standard for telephone circuit access and patching.

Building on its growing sales of jacks and plugs in the early 1970s, ADC introduced prewired, connectorized jackfields, wired assemblies and test equipment for telephone operating companies. By 1974 the company was on solid ground, and by 1976, ADC had become the largest independent supplier of test boards in the United States.

ADC's growing presence as a supplier to the telecommunications industry was significantly enhanced in 1983, when AT&T was ordered to deregulate by the federal government. By establishing the seven regional Bell operating companies (RBOCs) as independent entities, the U.S. market for telecommunications expanded by 90 percent. No longer forced to purchase their equipment from the Western Electric Division of AT&T, the RBOCs began to look for suppliers like ADC that had a reputation for quality and innovation in the marketplace. Over time, the RBOCs would become ADC's key customer base.

ADC's Evolving Facilities

1955 in a St. Peter, MN brewery

1960 in South Minneapolis

Today's World Headquarters in Eden Prairie, MN

To more effectively focus its resources on the emerging telecommunications market, ADC sold its magnetics business in 1984 and formally changed its name to ADC Telecommunications, capitalizing on the shift in technology from analog to digital, and becoming the industry leader in digital signal cross-connect devices.

In March 2004, ADC purchased the KRONE Group, a leading global supplier of copper- and fiber-based connectivity solutions and cabling products used in public access and enterprise networks. With the addition of KRONE employees, products and services, ADC now provides global scale and a broadened scope of products and services designed to serve public network and enterprise customers anywhere in the world.

Today, ADC has grown to become a leading global supplier of equipment and software for telecommunications, cable television, broadcast, wireless, and enterprise networks. ADC products perform critical functions that ensure the quality and reliability of broadband networks throughout the world.