The Washington Capitals have only played in the Stanley Cup Finals once and that was in 1998. The Capitals have never won the Stanley Cup in the franchise's History. Washington played the Detroit Red Wings and lost.
The Las Vegas Golden Knights are an expansion team this year so this is their first Stanley Cup run. They have set a few NHL records this season, should be interesting to see if they can win this year.
Of all the teams that are recognized as being part of the NHL's modern expansion era, none have won a Stanley Cup quicker than the Philadelphia Flyers. In their seventh season, 1973-74, the Flyers defeated the Boston Bruins to win the Stanley Cup.