Beginning as a small steam heat and plumbing shop in 1880, Ahern has since become one of the largest, most respected specialty contractors in the nation. For more than 130 years, we’ve focused on what matters most to clients to deliver value to their projects.

1880 - 1900

In 1880, David Ahern and his son John opened a plumbing business in downtown Fond du Lac, Wisconsin. The company, called D. Ahern & Son, focused on sanitary plumbing, steam, and hot water heating. Gradually, the family’s commitment to customer service and quality led the small store to the forefront of local industry.

1900 - 1920

The company continued to thrive under David and John’s leadership. Still focusing on local residential and light commercial work, John’s sons Tom and John E. ("Don") Ahern began to contribute their skills.

1920 - 1940

In 1921, John F. assumed control and incorporated the company, which he renamed J. F. Ahern Co. Early on, J. F. saw opportunities beyond the town of Fond du Lac. He and his sons, Tom and Don, sought out commercial, institutional, and industrial work throughout Wisconsin and the Midwest.

1940 - 1960

Ahern continued its climb in both sales and scope, taking on numerous municipal, governmental, and large institutional projects in Wisconsin and beyond.

1960 - 1980

Large industrial and institutional projects continued to account for the majority of company sales. Ahern began to climb the ranks of nationally recognized mechanical contractors, reaching number 65 in Domestic Engineering magazine’s 1978 "Book of Giants" – reporting annual sales of $13.4 million.

1980 - 2000

Ahern formed its Fire Protection Division in 1981, and began fabricating piping for external projects the following year. This timeframe also began Ahern’s fifth generation of family ownership.

2000 - Present

The company reached a milestone in 2004 when employment exceeded 1,000 people. Shifting trends in construction led to the formation of an Energy Solutions Department, as well as the construction of two of our own LEED recognized facilities: our corporate building (LEED Gold Certified) and our Milwaukee facility (LEED Gold Certified).
When Ahern celebrated its 125th anniversary in 2005, the Company produced a book that chronicled the history from its founding in 1880 through the present. In 2015, a second booklet was published in honor of the 135th anniversary that covered the decade following 2005. In reading these books and learning more about the Ahern story, you'll see that throughout decades of change and growth Ahern has remained focused on what we now identify as our Core Purpose.
Click here to view the 125th Anniversary Book
Click here to view the 135th Anniversary Book