Our William Hill review here focuses specifically on the online betting site launched for US customers in 2018. It should also be noted that the name “William Hill” can refer to any number of individual sportsbooks and international betting sites. William Hill now has retail operations in Nevada, New Jersey, Michigan, Illinois, Indiana, Delaware, Colorado, Iowa, Pennsylvania and West Virginia with more locations in the works. Today, William Hill is the largest sports betting operator in the United States. In 2012, William Hill spun off its US operations to establish William Hill US, a subsidiary targeting the retail sports betting market in Nevada. Alternatives To William Hill Sportsbook.William Hill Sportsbook Deposit Methods.William Hill Sportsbook In-Play Betting.