Answer: Horse Racing

When Dutch and English settlers brought the game we now call pool over to what would become the United States, it was still called billiards (as it was in Europe). It retained that name for centuries in the New World until the late 19th century.

There, a combination of circumstance and the way language morphs over time would collide to forever rename the table-based recreation in the mind of the public. Horse tracks had rooms for patrons to place bets, called pool rooms, because of the contribution of the patrons to the collective betting pool.

To help pass the time between races, proprietors began installing billiard tables to draw in and entertain their patrons. Eventually, the act of playing took on the name of the location in which the activity took place and the term “pool” came to be associated with the form of billiards played on the pocketed table we’re familiar with today.