Poker in the 20th century Poker may have caught on quickly in the US and attained some level of popularity in Britain in the 19th century, superslot โปร 100 but was only introduced to Europe in the 20th century. This was thanks to American soldiers who were sent to fight on behalf of the Allies during World War 1. Moving to the latter half of the 20th century, poker saw an increase in interest in poker thanks to the World Series of Poker (WSOP). The first WSOP tournament took place in 1970 and helped drive interest in the game in casinos across the US, but it wasn’t until the Californian legalization in 1987, and the Indian Gaming Regulatory Act in 1988, that poker became more mainstream.