Salads have a very long European history, but have only recently become popular in North America. Morris County Library's Food Timeline1 puts white kidney bean salad in 4th Century Jerusalem. The Association for Dressings and Sauces' History of Salad Dressings2 goes even farther back, asserting that the Babylonians put oil and vinegar on greens "nearly 2000 years ago".
Two significant events have lead to the popularity of salad in North America:
- Commercial availability of mayonnaise, starting in 19122.
- Awareness of nutrition combined with environmentalism and naturalism in the 1960s3.
3: McCoy, Robin. History of the American Salad <http://www.geocities.com/Athens/Rhodes/4190/salad.html>