The U.S. Department of Agriculture's National Agricultural Library offers a digital collection of pomological watercolors—illustrations of fruit cultivars commonly grown between the years 1886 and 1942. In those years, the department's Division of Pomology employed 21 artists to document fruit varieties in images that were then lithographed and used in USDA informational publications.
Author Tim Hensley writes that the 19th and early 20th centuries "are known to fruit historians as the golden age of American pomology." In 1905, a staff pomologist at the USDA cataloged 17,000 different apple names representing around 14,000 different varieties of apple grown in American orchards and backyards.
The digital collection contains some 4,000 images of apple varieties, many of which are now unfamiliar to American palates. The USDA's botanical artists, nine of whom were women, recorded all of the blemishes and discolorations they saw on the samples they painted.
With the standardization and industrialization of agriculture, the great preponderance of these apple varieties have dropped out of favor. In the past decade or two, some researchers, nurseries, and hobbyist "fruit sleuths" have made new efforts to identify and recultivate older varieties like these.