<|im_start|>user
When was rolling luggage invented?<|im_end|>
<|im_start|>assistant
Rolling luggage was invented by Bernard D. Sadow in 1970. His invention was described in a patent, numbered 3,653,474, which emphasized the growth of air travel as a motivating use-case. The purported inspiration for attaching wheels directly to the luggage was an observation by Sadow of a porter stacking luggage on a rolling cart.<|im_end|>
