Demonstration Sports at the 1912 Olympic Games
Demonstration sports were "officially" introduced at the 1912 Olympic Games in Stockholm. Many resources only list baseball and glima as demonstration sports at these games, though the The Official Report of the Olympic Games of Stockholm 1912 includes details of several other sports demonstrations that were organized by the Swedish Olympic Committee, to run at the same time as the Olympic Games.
An American team played against the host country Sweden, a match at the Östermalm Athletic Grounds on July 15th. The US team was made up of volunteers from the track & field team, the Swedes were represented by a local club Vesteras. On the next day two American teams played a second exhibition match. See more about Baseball exhibition matches at the Olympics.
Glima is an Icelandic national style of folk wrestling. A demonstration was held at the Olympic stadium at 7.30 on July 7th 1912. There was also a competition held at the Olympic Stadium on July 15. See more about Glima at the Olympics.
The Swedish Olympic Committee approved the "display of Boy Scouts, the Flat Racing and Trotting Races at Lindarängen, the display of Gotland games, the Icelandic “Glima”-Wrestling, a baseball exhibition match at the Östermalm Athletic Grounds, and Swimming displays in connection with the illuminations (fireworks displays) at Djurgårdsbrunnsviken Channel. In addition to this, there were several displays in gymnastics"
There could have been demonstrations of more sports, as there was a proposal by the Knickerbocker Whist Club of New York for a competition in whist (trick-taking card game developed in England); a proposal from Canada for a Lacrosse display and from the Olympic Committee of France, for Aeronautic competitions.