"The Diamond as Big as the Ritz" is the story of a man who owns a diamond so big his only goal in life is to safeguard its existence from the rest of the world. This means imprisoning those who discover it. It makes sense, then, that freedom is an important theme in the text. Part of the irony of this satirical story is that the diamond-owner is himself a prisoner of his own obsession with wealth. Because the story satirizes the expansion of America across the continent, there are implications as to our own founding history. Lastly, many read into "The Diamond as Big as the Ritz" parallels to immigration, since the estate containing the diamond (parallel to America) is closed off to all outsides who cannot be used or manipulated for gain.
When the story begins, John is imprisoned by his obsession with wealth; but by the end he is free.
John is never able to escape from his obsession with wealth. This is the "prison" which holds him.