"The coffee house, which originated in the Middle East around 1511, began simply as a place to enjoy an exotic drink, coffee, but soon evolved into a place that helped change the course of history." -Stefanie Spencer

Throughout history, the coffeehouse has been the place where people go to sample coffee, tea, and chocolate.  It is thought that the ideas that spread the American Revolution, and the revolutions across Europe may have originated in coffeehouses.  Different than a pub or tavern, coffeehouses have been a location for people of different social classes and different backgrounds to enjoy a beverage and discuss ideas with others.

The coffeehouse first originated with the origination of coffee--in the Middle East.  As coffee began to be traded throughout Europe and Africa, the coffeehouse was born.  The culture of the coffeehouse (due to the stimulating properties of caffeine) became one of political discourse as opposed to the "intoxicated" discussion at pubs and taverns which broke down as alcohol began to take effect.

As coffeehouses began to spread throughout the world, the coffeehouse also became a status symbol among intellectuals and the newly emerging "middle class."  In the coffeehouse, it was acceptable for people with different cultural and socioeconomic backgrounds to meet and share ideas, creating networks and connections, and essentially creating a powerful middle class that was much different from the traditional aristocracy.

...and the rest is history.

References:

The European Coffeehouse: a Political History