0 WHO WAS THE FIRST PRESIDENT TO ATTEND THE WORLD SERIES?

In 1915, Woodrow Wilson, the 28th president, became the first President to attend the World Series, where he and his fiance, Edith Gault, made their first public appearance since announcing their engagement.
The President insisted on paying for his own tickets.

Wilson, Woodrow: 1915 World Series. Photograph. Encyclopædia Britannica Online.

Resource:  whitehouse.gov