The Romans are often credited with inventing plumbing, but it was the Minoans, Mesopotamians, and Indus Valley civilizations who, about 4,000 years ago, engineered the world’s first sewer systems, complete with flushing toilets. In 1652, Boston was the first U.S. city with a water system; it used hollowed-out tree trunks. In 1804, Philadelphia introduced cast iron pipes. Alexander Cummings was awarded the first patent for a flush toilet in 1775. In the 1920s, tank-style toilets that used five to seven gallons per flush became popular, later improved by water-saving three-gallon versions in 1974.
While plumbing has advanced significantly, all these systems have one thing in common—they can clog.