1993 Florida Marlins
There have been rumblings for expansion in baseball for the last several years now. Las Vegas was an idea until the Athletics claimed it for the future, and places from Portland to Mexico to Montreal have been rumored at one point or another. Heck, Tampa Bay used to be a rumor before they finally got an expansion team in 1998, and now rumors are around the Tampa Bay may LOSE their team. For now, the state of Florida has two MLB teams, with Miami being the first city to try out non-spring baseball.
In 1993, the Florida Marlins began their existence along with the Colorado Rockies. The team was understandable bad. Manager Rene Lachemann could only do so much with his collection of castoffs and unproven youths. Hard to believe that within 5 years this team would be kings of the baseball world when they won the World Series, but it had to start somewhere. A few of those future champions were apart of the '93 team, completing the journey from newborn franchise to champions.
...And then the team decided to become an expansion team again in 1998, as if winning the World Series meant they had to hit restart on the roster, something they'd do again after winning in 2003. They play baseball on hard mode down in Florida, it seems. Only time will tell if the Rays pay by the same Florida rule, but first they need to win it all. Meanwhile, the Marlins have proven that their initial expansion effort was superior to their 1998 version.
The 1993 Marlins went 64-98 and finished 33 games back of the East Division winning Philadelphia Phillies. Despite being a brand new team, they avoided last place by 5 games (look away, Mets fans), but were bettered by their fellow expansion team, the Rockies, by 3 games. This would be their low point before winning the title in '97 as year by year they'd slowly improve into contention.