sandwich), sauerkraut (as on the reuben), coleslaw, or pickles. It is possible that after the creation of the hamburger by uniting the steak with the bread, vegetables were included to give the finished product a more "natural" appearance and taste. All of these condiments were incorporated into the classical image of the hamburger during its golden age, the 1940s. In some cases, the hamburger is prepared differently and distinctly to add regional flavor, as in the case of Tex-Mex style burgers, which are served with a side of chili con carne. French fries are an invention of the Low Countries, and Belgian historian Jo Gerard mentions that they originated around 1680 in both Belgium and the Spanish Netherlands, specifically in the area of "the Meuse valley between Dinant and Liège". The people of this region used to prepare meals with small amounts of fried fish, but when the river froze over and fishing became impossible, they would cut up potatoes and fry them in animal oil. French fries were introduced as a snack in American cafés during the early 19th century, but they did not become popular until large fast food companies such as McDonald's and Burger King incorporated them into their menus during the mid-20th century. The improvements in potato freezing technology made by J.R. Simplot of Idaho City in 1953, made the large scale production of French fries possible. Before the potatoes were frozen, however, they had still lost some of their flavor during frying, but new processes such as a further improved Simplot invention avoided this inconvenience by 1967, largely thanks to the use of a mixture of cow tallow and soybean oil. This allowed Simplot and McDonald's founder Ray Kroc to collaborate, resulting in ready-peeled potatoes from Simplot's farms being delivered directly to McDonald's kitchens, where they were fried and served to customers. Initially, however, there were safety concerns raised over some fries and the kitchens in which they were prepared, leading some companies, such as White Castle, to remove them from their menus during the 1950s. At the end of the 19th century, a new generation of cola emerged, a beverage that would soon join beer as the most traditional drinks served alongside the hamburger. The first recipe for Coca-Cola was invented in 1885 in Columbus, Georgia, by grocer John Pemberton. Originally called coca wine (the trademark was "Pemberton's French Wine Coca"), it may have