He played an important role in the breakup of AT&T while growing MCI into a US$9.5 billion in revenue entity that controlled 16% of the American domestic and international long distance market.

Bill was active in Ashley Boy Scouts and his troop which included his friends, Tim Klinges, Manus Cooney, Dave Cooney and George Frees, was one of the first group of Boy Scouts to go to Camp St. Andrew before it opened publicly in Tunkhannock, PA.[1] Bill's brother, Monsignor Andrew J. McGowan eventually ran Camp St.

After graduation from Harvard, McGowan began operating a consulting firm that specialized in rescuing troubled companies in the garment district of New York City.

In the role of venture capitalist, McGowan dealt with firms developing ultrasonic cleaning technology and electro-mechanical devices.

In his role as chairman, McGowan raised capital for the growing company and set up fifteen of the seventeen regional carriers that would form the basis of MCI's initial communications network.

Following the filing of MCI's 1974 lawsuit against AT&T, McGowan began cooperation with the U.S. Department of Justice which eventually led to a 1982 agreement leading to the divestiture of AT&T and the opening of the long distance telephone market within the United States.

[5] McGowan returned to his duties as MCI chairman after a six-month recovery, where he remained until his death on June 8, 1992, from another heart attack.