The first California raisins were produced in southern California during the 1850s using the Muscat of Alexandria variety. The industry soon moved north and was firmly established in the Fresno area by the 1870s.
Around 1876, a Scottish immigrant, William Thompson, grew a seedless grape variety, Lady deCoverly that was thin skinned, seedless, sweet and tasty. The first and only survived publicly displayed became known as Thompson’s seedless grape.
Thousands of acres of this grape have been planted in California to produce raisins, wine and table grapes.
History of raisins in United States