It only seems fitting that the largest diamond ever discovered in the United States be nicknamed “The Uncle Sam Diamond.” At 43.22 carats (or nearly 8.5 grams) the diamond was certainly quite a find--and the story of its discovery is just as astonishing as its size. At the time, the Arkansas Diamond Corporation was seriously indebted and on the verge of folding. The finding of the Uncle Sam diamond, however, sparked a wave of optimism that kept the company afloat. Then, in 1972, the state of Arkansas bought the mine and turned it into the Crater of Diamonds State Park--the world’s only publicly accessible diamond mine.