Origin of American Dream
coined 1931 by James Truslow Adams (1878-1949), U.S. writer and popular historian (unrelated to the Massachusetts Adamses), in "Epic of America."
[The American Dream is] that dream of a land in which life should be better and richer and fuller for everyone, with opportunity for each according to ability or achievement. It is a difficult dream for the European upper classes to interpret adequately, and too many of us ourselves have grown weary and mistrustful of it. It is not a dream of motor cars and high wages merely, but a dream of social order in which each man and each woman shall be able to attain to the fullest stature of which they are innately capable, and be recognized by others for what they are, regardless of the fortuitous circumstances of birth or position. [Adams]
Others have used the term as they will.
A phrase connoting hope for prosperity and happiness, symbolized particularly by having a house of one's own. Possibly applied at first to the hopes of immigrants, the phrase now applies to all except the very rich and suggests a confident hope that one's children's economic and social condition will be better than one's own.