The letter -- written by the Nobel-winning physicist to a New York businessman, Hyman Zinn, praising him for his efforts to help Jews escape persecution in Adolf Hitler's Germany -- sold for $13,936, almost double its estimate, the BBC reported Wednesday.
"It must be a source of deep gratification to you to be making so important a contribution toward rescuing our persecuted fellow-Jews from their calamitous peril and leading them toward a better future," Einstein wrote to Zinn.
Einstein fled Germany and came to the United States when Hitler rose to power in 1933.
The typewritten, hand-signed letter with Einstein's embossed Princeton University address and the original mailing envelope was sold in Los Angeles and had carried a reserve price between $5,000 and $7,000.
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