Answer:
The mysterious and disfigured Mr. Steward arrives to deliver the key to unlock the button, and tells Norma that if the button is pushed, she will receive $1 million in cash, but someone she does not know will die. He gives her $100 for allowing him to enter the house and voice his deal, and leaves.
The main ideas shaping US imperialism were "Manifest destiny" and the "White man's burden". Manifest destiny refers to the 19th century belief that the United States were meant to expand across North America because of the particular excellence of its (white) people and (democratic) institutions. This lead to the Trail of Tears, among other atrocities. Once the US reached the Pacific Ocean, new lands came into view (Puerto Rico, the Phillipines). Manifest destiny became entwined with the idea that "civilized" nations had a moral obligation to colonize other peoples, which Rudyard Kipling summed up in his poem "White Man's Burden". The tensions in this "benevolent imperialism" were never fully resolved; the US invasion of Irak was launched under similar pretenses (the invasion was "for the good" of those invaded). The idea that other peoples have a right to self determination regardless of their level of development has not yet become accepted by the great powers, including the US.