There is no such breed as Americana. There is a breed called Ameraucana, but they are not Easter Eggers. Easter Eggers are similar, but are not a standard breed and do not breed true.
X2 on the above. There is a good article at http://www.the-chicken-chick.com/2011/09/ameraucana-easter-egger-or-araucana.html explaining the difference between Araucanas, Ameraucanas, and Easter Eggers.