The NHL Board of Governors approved an expansion franchise for Las Vegas on Wednesday. Since the first round of expansion in 1967, the League has grown from the Original Six to 31 teams.

1942: With the demise of the Brooklyn Americans, the NHL's Original Six era begins. The Boston Bruins, Chicago Black Hawks, Detroit Red Wings, Montreal Canadiens, New York Rangers and Toronto Maple Leafs make up the League for the next 25 seasons.

1967: The NHL adds six teams, the largest expansion in professional sports history. The addition of the California Seals (later renamed the Oakland Seals and then the California Golden Seals), Los Angeles Kings, Minnesota North Stars, Philadelphia Flyers, Pittsburgh Penguins and St. Louis Blues brings the NHL from six to 12 teams.

1970: The NHL expands to 14 teams by adding the Buffalo Sabres, owned by brothers Seymour Knox III and Northrup Knox, and the Vancouver Canucks, owned by Tom Scallen. Vancouver had been home to the Millionaires, which won the Stanley Cup in 1915, two years before the founding of the NHL.

1972: The New York metropolitan area gets a second NHL team and the South gets its first. The New York Islanders, based in the Long Island town of Uniondale, N.Y., join the NHL as do the Atlanta Flames, though the team moves to Calgary in 1980.

1974: The pattern of adding of two teams every two years continues when the Washington Capitals and Kansas City Scouts join the NHL. However, the Scouts play only two seasons in Kansas City before moving to Denver and being renamed the Colorado Rockies; in 1982, the franchise moves again and becomes the New Jersey Devils.

1978: Two years after the California Golden Seals move to Cleveland and are renamed the Barons, they merge with the North Stars. That reduces the number of teams in the NHL from 18 to 17. The North Stars move to Dallas in 1993 and are renamed the Stars.

1979: The NHL takes four teams from the World Hockey Association. The addition of the Edmonton Oilers, Hartford Whalers, Quebec Nordiques and Winnipeg Jets brings the NHL to 21 teams. The Nordiques move to Denver in 1995 and are renamed the Colorado Avalanche, the Jets move to Phoenix in 1996 and become the Phoenix (now Arizona) Coyotes, and the Whalers relocate in 1997 and are renamed the Carolina Hurricanes, based in Raleigh, N.C.

1991: A new era of NHL expansion began with the addition of the San Jose Sharks, bringing the League to 22 teams.

Video: NHL awards expansion franchise to Tampa

1992: The NHL expands again with the addition of the Ottawa Senators and Tampa Bay Lightning. The original Senators had played in the NHL from 1917-34. The Lightning are the first NHL franchise in Florida.

1993: The League adds its 25th and 26th teams, the Florida Panthers (based in Miami) and Mighty Ducks of Anaheim.

1998: The Nashville Predators join the NHL, bringing the number of teams to 27.

1999: Nineteen years after the departure of the Flames, the NHL returns to Atlanta with the addition of the Atlanta Thrashers, the League's 28th team. However, the franchise relocates to Winnipeg in 2011 and becomes the second iteration of the Jets.

2000: With the addition of the Columbus Blue Jackets and Minnesota Wild, the League reaches 30 teams. The Wild, who play in St. Paul, Minn., bring the NHL back to Minnesota seven years after the North Stars depart for Dallas.

2016: NHL commissioner Gary Bettman announces the addition of a franchise in Las Vegas that will begin play in the 2017-18 season, bringing the NHL to 31 teams. It is the first major professional sports team in Las Vegas.