Respuesta :
The main stems
of 38 rivers in the United States are at least 500 miles (800 km) long.
The main stem is "the primary downstream segment of a river, as
contrasted to its tributaries".[1] The United States Geological Survey (USGS) defines a main-stem segment by listing coordinates for its two end points, called the source and the mouth. Well-known rivers like the Atchafalaya,[2] Willamette,[3] and Susquehanna[4] are not included in this list because their main stems are shorter than 500 miles
Answer:
Mississippi River
Explanation:
The Mississippi River is the longest in North America. Its name, which means "Father of the Waters", was given by American Indigenous. Writer Mark Twain's works made this river part of the legendary traditions of the United States.
The Mississippi River begins on Lake Itasca in upstate Minnesota and flows south. Near Saint Louis, Missouri, the muddy Missouri River joins the Mississippi. Further, in Cairo, Illinois, the Mississippi meets the rushing Ohio River. The Mississippi enters the Gulf of Mexico near New Orleans, Louisiana.
The Mississippi River itself is 3,780 kilometers long. In addition to the Missouri River, which is its main tributary, the total length of the waterway is estimated at 5,971 kilometers, making it the fourth longest watercourse in the world.