Which of these events was not a first at the 1920 Summer Olympics?

The 1920 Summer Olympics officially known as the Games of the VII Olympiad, were an international multi-sport event in 1920 in Antwerp, Belgium. In March 1912, during the 13th session of the IOC, the bid on the behalf of Belgium to host the 1920 Summer Olympics was made by Baron Édouard de Laveleye, president of the Belgian Olympic Committee and of the Royal Belgian Football Association.

These Olympics were the first in which the Olympic Oath was voiced, the first in which doves were released to symbolize peace, and the first in which the Olympic Flag was flown.

The USA won 41 gold, 27 silver, and 27 bronze medals, the most won by any of the 29 nations attending. Sweden, Great Britain, Finland, and Belgium rounded out the five most successful medal-winning nations.