LeRoy T. “Roy” Carlson Sr., who began accumulating local telephone exchanges in the 1950s and along with other Carlsons built a telecommunications firm that controls U.S. Cellular and had $5 billion in revenue last year, died May 23, a week after he turned 100. His death, in Evanston, was announced by Chicago-based Telephone & Data Systems, which he founded in 1969. U.S. Cellular was formed in 1983 and went public in 1988, with TDS retaining an 80-plus percent stake. Carlson, his son LeRoy Jr., known as Ted, and other family members retained an iron grip on TDS through ownership of special voting shares. Following a Harvard MBA and service in World War II, Roy Carlson worked in managerial positions, real estate and other ventures before buying Suttle Equipment, a supplier that was his entree to the telecom industry, according to TDS. He retired as chairman in 2002. Ted Carlson has been president and CEO since 1986; another son, Walter, a partner at law firm Sidley Austin, is chairman.