According to sources, a customer said his french fries were too thick, so Crum cooked the customer what he wanted by slicing potatoes paper-thin, over-frying them to a crisp, and seasoning them with an excessive amount of salt. He expected the customer to dislike them very much, but he actually loved them. The chips became popular and subsequently known as "Saratoga chips" or "potato crunches". Crum opened his own restaurant in 1860 with the profits he made selling his new chips. They remained a local delicacy until the Prohibition era, when an enterprising salesman named Herman Lay popularized the product throughout the Southeastern United States.
According to urban legend, the hard-to-please customer was prominent railroad magnate Cornelius Vanderbilt. However, it was more than likely a much more obscure customer. An early source for the story identifies Vanderbilt as a regular customer, but not as the unintentional co-originator of the famous snack.
In 1832, a recipe for fried potato "shavings" had been printed in the U.S. in a book explicitly derived from an even earlier English collection.
A biography commissioned by Crum in 1893 made no mention of his purported invention. It is possible that Crum's sister, Katie Speck Wicks, either made the first discovery herself or in conjunction with Crum. A contemporary source gives credit to Cary Moon's wife, Harriet, stating that she developed the side dish over time.
Detractors of Crum being the inventor of potato chips claim that, even if those prior to him did not call them potato chips, a sliced potato cooked in hot oil and served sprinkled with salt existed before he first made them. Existing cookbooks from that time contradict the claims that Crum and/or his sister invented potato chips. William Kitchiner's book, The Cook's Oracle, includes a recipe for what could be described as a potato chip, even though the cookbook does not use that term to describe it. N.K.M. Lee's cookbook, The Cook's Own Book, has a recipe that is extremely similar to Kitchiner's.
- Snopes, which lists its sources
- Early Lake Houses Saratoga, New York (Reminiscences of Saratoga compiled by Cornelius E. Durkee, The Saratogian 1927-28 
- Burhans, Dirk, 2008. Crunch! A History of the Great American Potato Chip, Terrace Books (Univ. of Wisconsin Press), Madison, WI, pp. 15-21.
- Civil War Recipes and Food History - The Potato During the Civil War
- History of Saratoga County, New York. Nathaniel Sylvester
- Invented in Saratoga County. Timothy Starr, 2008
- New York Times
- Kitchiner, Dr. William, 1822. The Cook’s Oracle; Containing Receipts for Plain Cookery, on the Most Economical Plan for Private Families: Also the Art of Composing the Most Simple and Most Highly Finished Broths, Gravies, Soups, Sauces, Store Sauces, and Flavouring Essences; the Quantity of each Article is Accurately Stated by Weight and Measure; the Whole Being the Result of Actual Experiments Instituted in the Kitchen of a Physician, 4th ed. A. Constable and Co. of Edinburgh, London, 464 pp. (See p. 208 for potato chip recipe. This is supposed to be the first American edition.)
- Lee, N.K.M. (A Boston Housekeeper), 1832. The Cook's Own Book: Being A Complete Culinary Encyclopedia: Comprehending All Valuable Receipts For Cooking Meat, Fish, And Fowl, And Composing Every Kind Of Soup, Gravy, Pastry, Preserves, Essences, &c. That Have Been Published Or Invented During The Last Twenty Years. Particularly The Very Best Of Those In The Cook's Oracle, Cook's Dictionary, And Other Systems Of Domestic Economy.Diamond Mb With Numerous Original Receipts, And a Complete System of Confectionery, Boston, Munroe and Francis; New York, Charles E. Francis, and David Felt.