A waterway is any body of water that people can use for travel or transportation. Rivers, canals, and straits are all waterways. The Mississippi River is one of America's most important waterways, carrying cargo ships loaded with grain, coal, and other goods from the middle of the country down to the Gulf of Mexico.

Some waterways are natural, carved by flowing water over millions of years. Others are artificial, dug by human effort. The Erie Canal, completed in 1825, created a waterway connecting the Great Lakes to the Atlantic Ocean, making New York City a booming center of trade. The Panama Canal cuts through Central America, creating a shortcut between the Atlantic and Pacific Oceans that saves ships from sailing thousands of extra miles around South America.

For thousands of years, waterways were the highways of the world. Moving heavy cargo by boat was far easier than hauling it over land by wagon. Even today, ships carry more goods than trucks or trains because water transportation remains efficient and economical. Cities like Venice, Amsterdam, and Bangkok grew around networks of waterways that served as streets.

When you hear that a waterway is navigable, it means boats can actually travel through it. A shallow creek might be a waterway in theory, but if it's too rocky or narrow for boats, it's not very useful for transportation.