United States Cellular Corporation (doing business as UScellular) is an American mobile network operator. It is a subsidiary of Telephone and Data Systems Inc. (which owns an 84% stake). The company was formed in 1983 and is headquartered in Chicago, Illinois. UScellular is the fifth-largest wireless carrier in the United States, with 4,740,000 subscribers in 426 markets in 23 states as of the third quarter of 2022. It was previously known as United States Cellular and U.S. Cellular. Timeline 1980s & 1990s United States Cellular was founded as a subsidiary of Telephone and Data Systems Inc. (TDS) and incorporated on December 23, 1983. In 1985, the company began operations in Knoxville, Tennessee (June), and Tulsa, Oklahoma (August). Don Nelson was named the first president in 1987 and TDS took the company public in 1988 where United States Cellular adopted USM as its ticker symbol on the American Stock Exchange. In 1999, United States Cellular relaunched under the “U.S. Cellular” brand name and image across all markets nationwide. 2000s Don Nelson retired and Jack Rooney took over as CEO. In 2001, U.S. Cellular received the Wireless Titan Award as the top wireless carrier in terms of customer service from Wireless Review magazine. The company purchased PrimeCo Wireless Communications in 2002 and launched in the Chicago area on November 22. It built on this growth by signing Chicagoan Joan Cusack as national spokesperson. In January 2003, U.S. Cellular acquired naming rights to the baseball stadium used by the Chicago White Sox. Formerly known as Comiskey Park, the stadium was officially renamed U.S Cellular Field (it was renamed Guaranteed Rate Field in 2016). That same year, U.S. Cellular and Cingular (now owned by AT&T Mobility) exchanged wireless assets and U.S. Cellular received new spectrum in markets of 13 states that were adjacent to or overlapped existing operations in exchange for its Georgia and northern Florida licenses. U.S. Cellular also launched Easyedge, its suite of wireless data services. In 2005, U.S. Cellular entered the St. Louis market, making it the second largest market U.S. Cellular served, after Chicago. In October of 2008, U.S. Cellular launched Mobile Broadband, a service enabling customers to access data on its cell phones 10 times faster than before. It brought DSL-like service and capabilities to customers through EVDO (Evolution-Data Optimized) technology, commonly referred to as 3G. As of Q2 2008, U.S. Cellular was preparing to roll out 3G/EVDO revision