SportsChannel is the collective name for a former group of regional sports networks in the United States that was owned by Cablevision, which from 1988 until the group's demise, operated it as a joint venture with NBC. Operating from March 1, 1979 to January 27, 1998, it was the country's first regional sports network, and along with Prime Network, was an important ancestor to many of the regional sports outlets in the U.S., particularly Fox Sports Networks and Comcast SportsNet. At its peak, SportsChannel operated nine networks serving several of the nation's largest cities including New York City, Los Angeles, Chicago and Philadelphia. History SportsChannel's origins date back to 1976, when Cablevision launched Cablevision Sports 3 (the "3" referencing its original channel slot on the provider), a sports network carried on the company's New York City area system. The network originated the SportsChannel brand on March 1, 1979, when it changed its name to SportsChannel New York. The network carried games from several New York area sports teams including the New York Yankees and New York Mets Major League Baseball franchises and the NBA's New Jersey Nets. One of the notable accomplishments from the channel's early days was inking one of the earliest cable deals with a pro sports team when they signed a contract to broadcast games on cable for the National Hockey League's New York Islanders in 1978 while still known as Sports 3. The network expanded to other regions with the launches and purchases of additional networks throughout the 1980s; the first expansion occurred when Cablevision signed a deal to televise the Chicago White Sox in 1981. However, this new network would be short-lived as the White Sox launched SportsVision the following season. Cablevision's subsidiary Rainbow Media's purchased Boston-based PRISM New England in 1983, relaunching the network as SportsChannel New England. Shortly after, Cablevision formed a partnership with The Washington Post which gave the Post a 50% interest in SportsChannel. By the end of the year, the Rainbow/Washington Post partnership purchased Philadelphia-based PRISM and SportsVision, affiliating them with SportsChannel (although the SportsChannel Chicago brand would not reappear until 1989). The White Sox returned to Cablevison, now with the addition of the Chicago Blackhawks and Chicago Bulls. In 1984, CBS entered the partnership in a deal that gave each of the three companies a one-third interest in three of the four networks and a one-sixth interest in SportsChannel