CREATE TABLE table_name_19 (round INTEGER, nationality VARCHAR(255), college_junior_club_team__league_ VARCHAR(255))
Which Round has a Nationality of united states, and a College/Junior/Club Team (League) of breck school (ushs)?
    
SQL: SELECT MIN(round) FROM table_name_19 WHERE nationality = "united states" AND college_junior_club_team__league_ = "breck school (ushs)"