These leagues are presently broken into geographical areas. The green is called the New England, Blue is called the Empire, Light blue is Eastern Penn, and brown (Virginia and Maryland is called Capitol and Florida is at the bottom right. In order for the USA national team to get better the players have to get groomed in these leagues. These leagues are always changing and growing which is a good thing.
The Rugby Sevens is the other half of Rugby that the USA is much better at.