Among the items the Chinese railroad workers brought with them to the States were various medicines — including snake oil. Made from the oil of the Chinese water snake, which is rich in the omega-3 acids that help reduce inflammation, snake oil in its original form really was effective, especially when used to treat arthritis and bursitis. The workers would rub the oil, used for centuries in China, on their joints after a long hard day at work. The story goes that the Chinese workers began sharing the oil with some American counterparts, who marveled at the effects.
The color cover for Clark Stanley's Snake Oil Liniment. It features a description of the product's uses, and Mr. Stanley wearing a hat with two snakes surrounding him. Clark Stanley's Snake Oil Liniment, True Life in the Far West, 200-page pamphlet, illustrated, Worcester, Massachusetts, c. 1905. Image sourced from Wikimedia Commons. Available here.