A Chinese pastime, mah jongg became a popular American parlor game in the 1920s. So many people were playing and creating unique table rules that it became difficult to play with others.

In 1937, Jewish women in New York City formed the National Mah Jongg League, codifying American mah jongg rules and kicking off a resurgence in popularity. The league sells an annual mah jongg card ...

Social media also plays a role; the Facebook group, Mah Jongg: That’s It ... New York City sought to standardize the rules of what is now called “American Mahjong” and formed the National ...