All four of Philadelphia's major professional sports teams played in the championship game or series, in their respective sports, following the 1980 season: The 1980 Philadelphia Phillies won the World Series, while the 1980 Philadelphia Eagles lost Super Bowl XV, the 1979-80 Philadelphia 76ers lost the NBA Finals, and the 1979-80 Philadelphia Flyers lost the Stanley Cup Finals.

Can we conclude that has a city ever won all championships in one year?
no