WHY PEOPLE IN SOUTH AMERICA DON'T CALL THEMSELVES AMERICANS INSTEAD ARE CALLED BY THE STATES THEY ARE FROM?

SUCH AS THEY ARE KNOWN AS VENEZUELANS, BOLIVIANS, ETC. WHEREAS PEOPLE IN NORTH AMERICA CALL THEMSELVES AMERICANS AND NOT BY THE VARIOUS STATES THEY ARE FROM, SUCH AS CALIFORNIANS, IOWANS, TEXANS, ETC.