Theresia Wilhelm, formerly of Illinois, passed away Thursday morning, January 21, 2021 at Terrace Place. She was 83 years old. Theresia was born December 7, 1937 in Yugoslavia, the daughter of Rudolph and Maria Backes. In 1956, she was united in marriage with Franz Wilhelm, and the couple immigrated to the United States in 1959. Theresia is survived by her husband Franz and their daughters: Eva (William) Rohrer of Grays Lake, IL, Lainie (Anthony) Rzadzki of Sheboygan Falls and Maria Mathews of Gurnee IL. She is further survived by grandchildren, other relatives and friends. According to Theresia's wishes, a private family memorial service will be held.