The actual date of when poker was initially played has never been known although many historians date a similar card game being played back in the 15th century that's similar. Modern poker took off in the 1970's when the World Series of Poker was developed and over the years poker has become one of the biggest hobbies in the world. When tournaments initially started back in the 70's there were not really that many players in the events and the same people always played each other.
Nowadays poker is played by millions of people around the world and we can thank the early pioneers for keeping the game alive in certain parts of the world. Las Vegas is still home to the biggest poker events of the year, but many other gambling destinations around the world have been putting up big numbers as well such as Macau. With the advancement of technology poker has been able to transform into a game that use to be only played in casinos and can now be played practically everywhere as long as you have a connection to the internet.
The major tournaments that use to feature fewer than 100 poker players are now filled with 1000's of hopefuls every year with tons of money on the line. With the current popularity of certain poker events all it takes is one victory to secure a lifetime bankroll and sponsorships. Poker has finally been accepted by the masses and it's not frowned upon if you play poker nowdays whereas 25-50 years ago it was almost unheard of to play poker.