What drew the immigrants to the united states?

the monroe doctrine is the best known u.s. policy toward the western hemisphere. buried in a routine annual message delivered to congress by president james monroe in december 1823, the doctrine warns european nations that the united states would not tolerate further colonization or puppet monarchs.

the missile gap was the cold war term used in the us for the perceived superiority of the number and power of the ussr's missiles in comparison with its own (a lack of military parity).