Matt Koppelman expanded on his previous map of Seattle Sounders FC players, this time including all rostered players in the MLS era of the team. Zooming in you can make out the high density in the Seattle era. American Soccer hotbeds of Southern California and the greater NYC metro area are also strongly represented. Scandinavia gets some love as well.
With Sounders 2 joining the system this year the number of players from the Puget Sound should increase dramatically, as should number from the Caribbean (Ezra Hendrickson has strong connections there and USL salaries are compelling).
One of the interesting things to see by putting all the players on one map is that despite getting players from throughout the world, there are still vast swaths of Earth that have yet to enjoy seeing a Sounder from their nation.