Engraved uncolored comparative view of the known Lengths of the Principal Rivers in the World.
In the 19th century, Missouri is considered the longest river in the world.
The Missouri River, a tributary of the Mississippi River, is 161 kilometers (100 miles) longer. Some currently describes the Mississippi River as being the 3rd longest river in the world if the length of Missouri and Ohio Rivers are added to the Mississippi’s main stem.
For most of the last century, the Nile has been considered the world’s longest river. The length of the Nile River is approximately 6650 kilometers (4132 miles). Brazilian scientists believe that the Amazon River is actually longer than the Nile by 105 kilometers (65 miles).