Hammes started his career with the
Trammell Crow Company in 1974 and credits
Trammell Crow as a career mentor. While serving in this role, he was involved in the Milwaukee Center development project. Hammes was also a member of the company's management board. He told the Milwaukee Business Journal that the health care sector represented a substantial percentage of gross national product at the time, and it made sense to allocate resources there. Hammes has also been personally involved with his company's construction of sports facilities, including the renovation of
Lambeau Field in Green Bay and the development of the
U.S. Bank Stadium in Minneapolis. Hammes continues to serve as chairman and CEO of Hammes Company.
Marquette University (board of trustees since 2014), the
Medical College of Wisconsin (since 2000),
Teach For America-Milwaukee, the University of Wisconsin Foundation,
Greater Milwaukee Committee, WiCab Inc., and the
YMCA of Metropolitan Milwaukee. In September, 2000, the investment board purchased $8.3 million worth of distressed bonds from Heartland Advisors, a Milwaukee-based firm where Hammes served as an independent director. While Hammes referred the state board's staff to Heartland officials, he recused himself from the consideration process for the investment because of a conflict of interest. Hammes involvement in Heartland's recommendation resulted in criticism from the co-chairman of the state legislature's Joint Audit Committee,
Gary George. In October 2000, the funds in which the state invested lost a combined $62 million in value. A report by the Wisconsin State Auditor issued in November, 2001 did not find any evidence that Hammes had influenced the investment decision. In December 2003, the SEC issued a consent order requiring Heartland's independent directors, including Hammes, to cease and desist violating securities laws, which they agreed to without admitting or denying any wrongdoing. He is also an owner of the Lakeshore Chinooks, a Mequon, Wisconsin-based baseball team in the Northwoods League. In 2015, Hammes and members of his family purchased a golf course known as The Bog in
Saukville, Wisconsin through Milwaukee B & E Partners I LLC, an affiliate of Hammes Company. == Personal life ==