A Business Executive
Despite being a mother of six, Mary managed to pursue a professional career. In 1903 she was promoted to president of M&H. Mr. Hegeler, now in his late 60s and devoted to his publishing company, naturally passed on the zinc business to his loyal and competent daughter (less loyal were his sons Julius and Herman who attempted to secretly sell the business while their father was on vacation in 1902). From Mary’s point of view, the offer of a “vocation”—to which she once referred in her letter to Gisela—was perhaps welcome not simply out of respect for her father, and less as a means to supporting herself, but as an outlet for expressing an “independence of ideas and thought.” At any rate, she was an ideal candidate for the position given her life-long apprenticeship as a zinc woman, high-level of education in engineering, and managerial experience as a board member.
While M&H continued to grow so did Mary’s responsibilities as its chief executive. As president she had full executive control of the business and handled important administrative matters such as approving purchases and plans for construction, examining financial records, and overseeing the legality of contracts. In the 1910s, she oversaw 900 employees and made decisions about their wages and safety. For example, regarding work at the mines, she determined the methods of fire fighting in the tunnels and the technology of the hoisting apparatus. She also expresses in letters to her son in March, 1909 her concern about air quality and flooding.
Adding to all of her executive responsibilities at M&H, her father made her a trustee of the Open Court. He put her in charge of $600,000, which she grew to $800,000 from 1900–1913. Furthermore, she was made a director of the La Salle & Bureau County Railroad. The short six-mile stretch of rail was created by Hegeler and Matthiessen to serve as a transportation link between the company and a major railway junction northwest of town.
It is difficult to imagine that Mr. Hegeler when he passed away on 4 June 1910 was anything but proud of his daughter and confident that his legacy was in safe hands. Although members of the Matthiessen family claimed the presidency in 1913, she fought them in a legal battle. From 1917–1933 she would serve as the secretary of the company until finally again serving as president from 1933–1936. In 1924 she helped orchestrate a buyout of the Matthiessen family, and during the 1930s, she helped guide the business through the tumultuous period of the Great Depression.