Hubert Cecil Booth invented the first powered vacuum cleaner after seeing a demonstration of a machine that blew dust off chairs. He realized it would be more effective to suck the dust through a filter. His first machine, the 'Puffing Billy,' was so large it had to be pulled by a horse and parked outside houses while long hoses were fed through the windows. It was powered by a gasoline engine. Later, James Spangler, an American janitor with asthma, created the first portable electric vacuum cleaner using a pillowcase as a filter. He sold the patent to his cousin's husband, William Hoover, whose name became synonymous with the device. The vacuum cleaner revolutionized domestic hygiene by removing dust and allergens from the home rather than simply moving them around with a broom or duster.