Baseball in Wartime
Professional baseball has been affected by most all of the major wars in US history. From WWII to the Korean War the sport was changed in some way. Some changes being as little as a few players going to war or pretty much an entire shut down of the league.
The president at the time was Franklin Roosevelt and he made sure that baseball would be continued to be played in the US. He believed this because it gave the citizens something to watch and be entertained by.
After most of the men went off to war and Major League baseball started to die down a new league was created, the All American Girls Professional Baseball League. This league was started by Phillip Wrigley as a way to keep the Major League parks from being torn down due to loss of attendance and use. This ended up being a good idea for team owners who had previously done everything they could to keep the stadiums in use such as Ski Jumping in Wrigley Park.
The first Major League Baseball player to join the military was Hugh Mulcahy. Mulcahy is famous for his saying "My losing streak is over for the duration, I'm on a winning team now." Mulcahy was in a major pitching slump which led him to leave the Major Leagues for the time being to join the US Military in WWII.
In the end the wars did not have too much of an impact on the sport in the long run, but during that time it was a very big deal especially in WWII. Baseball is still America's past time as it has been since the early 1900s.