Pelé singlehandedly pulled the sport into the modern age and was responsible for its explosive growth outside its traditional boundaries.
Millions of American kids started playing because of how he exhibited the sport and projected its excitement. NASL was basically a vehicle for Pelé. It sucks that league didn't last. But MLS came along and some of those kids in the 70s went on to play in those early MLS years.
There were early soccer leagues in the US back in the teens and 20s and 30s. They died, sadly. But Pelé changed everything and set the stage for what we have now in the United States, which is a thriving domestic league and a dynamic young national team with a bright future.
It's all because of the impact of Pelé.