Trades can be huge in baseball. Deals can contain tons of players, and they usually contain a host of prospects, too. The bigger they are, the more impactful they can be. The Los Angeles Dodgers and Chicago Cubs once did a trade that was relatively unprecedented in 1957, and it hasn't been matched since. They traded entire minor league rosters. Is that possible now?
The Dodgers and Cubs swapped minor league rosters, which is unheard of. For starters, if minor league prospects are traded, it is often for major league players. Swapping minor league players is rare, let alone an entire team.
The Dodgers were about to move West and the Cubs just wanted to change things, so both teams decided to make this insane trade and swapped their entire 25-man minor league rosters. Can that still be done today?
Can you trade entire rosters in baseball?
Technically, teams could still trade entire rosters in baseball. There are very few limits on trading, and they mostly apply to which players are applicable. If a team had a player that was restricted, whether by MLB rules or by a no-trade clause, they couldn't be part of such a swap. If no restrictions stood in the way, it is theoretically possible.
However, there are a multitude of reasons why this wouldn't happen. For instance, if the Los Angeles Angels wanted to trade their entire roster to shake things up since they've been pretty terrible for a decade, they would have a hard time finding a partner. What other team would want their team in place of theirs? Maybe the Oakland Athletics, but the Angels likely wouldn't do that.
Furthermore, an entire roster is not without a player each team might want to keep with very few exceptions. In that hypothetical trade scenario, the Angels would want to keep Mike Trout.
They might also want to keep Shohei Ohtani if they re-sign him, so there's really no reason to swap entire rosters with anyone. Even in the minor leagues, as the Dodgers and Cubs did, every team has prospects they want to keep, and with farm system rankings, every team has value in their minor leagues that they'd likely not want to switch with anyone.