The World Series was in town, with the Cubs hosting Babe Ruth and the Boston Red Sox. The Chicago games were played at Comiskey Park, the home of the White Sox, instead of their new home at Wrigley Field, what was called Weegham Park at the time, because it held more fans. But in a city jittery over the bombing and weary from the war, Game 1 that day attracted fewer than 20,000 fans, the smallest World Series crowd in years.
A few fans began to sing. Then others joined in "and when the final notes came, a great volume of melody rolled across the field," the Times reported. And when it ended, "onlookers exploded into thunderous applause and rent the air with a cheer that marked the highest point of the day's enthusiasm." The Red Sox went on to win the game and the series, part of a Cubs' championship drought that ended up lasting 108 years but was a mere decade old in 1918.
Please read this timely ESPN article.1918 World Series key in US love affair with national anthem http://www.espn.com/espn/wire?section=mlb&id=19797748