Legend has it that California discovered the commercial potential of raisins quite by accident. In 1873, a freak hot spell withered the grapes on the vine. One enterprising San Francisco grocer advertised these shriveled grapes as "Peruvian Delicacies" and the rest is history. In 1876, Scottish immigrant William Thompson grew a seedless grape variety that was thin skinned, seedless and sweet. Today over 90 percent  of California raisins are made from Thompson seedless grapes and half the world’s supply of raisins are grown in California.

California League Of Food Producers