William was the 3rd child and oldest son of Jacob and Catherine Hassinger. He graduated from Rensselear Polytechnic Institute in Troy, New York in June 17, 1885 with a major in civil engineering and chemistry. For 2 years following college, he was Chief Chemist for the Youngstown Steel Company of Youngstown, Ohio but Birmingham attracted him during its “Boom Period” because of the abundant local coal, iron ore, and limestone.
Then in 1887 at almost age 24, he incorporated and formed the Alabama Rolling Mill Company, established a plant on 30 acres in the Gate City area of Birmingham, built an all iron sheet metal building with numerous furnaces and machinery, and started production a year later in February 1888, making pig iron bars, bonds, hoops, cotton-ties, light T’s and street rails.
The next year at age 25 in 1888, he became a Director of the Henderson Steel Company that made steel from the local coal, iron ore, and limestone.
In 1896 he became a Director of the First National Bank of Birmingham and remained in that capacity until his death in 1935. It was his daily habit to visit the bank everyday. Officers grew to look for these visits, it is said.
In 1898, he and his wife Virginia completed construction and moved into 2028 Highland Avenue South, Birmingham, AL in what was the “Silk Stocking Row” of the City.
In 1899 he sold his Alabama Rolling Mill Company to Republic Iron and Steel Company and became the Southern territory manager and later Executive Vice President of Republic Iron and Steel. Under his direction, coal from the Big Seam was first washed and coked. He also built the first large furnace of 250 tons capacity.
He retired from Republic Iron and Steel in 1906 and reorganized the bankrupt Southern Steel Company as the Southern Iron and Steel Company and became its President. He remodeled and enlarged steel furnaces and it became the Gulf States Company. At this time he also helped organize the American Cast Iron and Pipe Company and served on its Board.
In 1916, he became a member of Board of Directors of the Alabama Power Company and was a pioneer in securing electricity for industrial and domestic use. In the Artist Studio below, see the “History of Electricity in Birmingham” of devices used from the first 1905 arrival of electricity on Highland Avenue up to the current time, in honor of his contributions.