There are many soccer leagues in the US. Anybody can play soccer no matter where they are or how old they are. There are club teams for children and adult leagues for adults. You just have to search around and find out what leagues are in you area.
Two, the MLS and COPA America.
there are about 4 kids, teens, champion, adult
It's almost the same: both countries have professional and minor soccer leagues with 20+ professional teams.
There are too many to count. There are dozens and dozens of basketball leagues, a few American football leagues, soccer leagues, many baseball leagues, and so on. There is no kept count of professional athletes.
The Negro leagues were US professional baseball leagues. The term is usually used to include 7 leagues, also called "Negro Major Leagues" which began in 1920.
As far as I know, there are two major ones in the US.
Total Professional Teams 76 Mens teams include 12 from Major League Soccer (MLS) 12 from the First Division United Soccer League (USL) 9 from the Second Division United Soccer League (USL) 6 teams in the Major Indoor Soccer League (MISL) Womens teams include 37 teams in the W-League a part of the USL
many
The USA soccer team is some what similar to a college team, process wise. They do both recruitment and they also have tryouts for their other strings. They recruit off of college teams and other minor leagues, but mostly college.
I think it is the United States academy because they have some the biggest international tournaments and also they many of their players make it into division 1 and 2 leagues, the USL, and the MLS and clubs from other countries
There 12 leagues, all in Pennsylvania.