It is well known that the game of basketball was created by James Naismith at the International YMCA Training School (now Springfield College) in Springfield, MA, USA, and that the first game was played on December 21, 1891. Since then, the game has gained wide popularity in the USA, despite the fact that for a time it was denounced as an activity that ran counter to "YMCA philosophy". This essay attempts to trace the very beginnings of the game and to identify the major factors responsible for its growth into a top global sport. It can be concluded that (1) Naismith's original concept for the game of basketball has indeed lived up to its "unfailing potentiality" for development as an enjoyable sport. (2) The YMCA made a leading contribution to the cultivation of physical education at that time, and to the rapid popularization of the game through their network in the USA. (3) The social and cultural changes in the last two decades of the 19th century in the USA led to an awakening of a new era of physical education and sport. Thus the game of basketball, originally designed to be played as an indoor ball game during the winter season to sublimate students' "play instincts" at the International YMCA Training School at that time, finally grew to become a global sport.