What does the name of Mississippi River mean?

The word Mississippi itself comes from Misi zipi, the French rendering of the Anishinaabe (Ojibwe or Algonquin) name for the river, Misi-ziibi (Great River).

In the 18th century, the river was the primary western boundary of the young United States, and since the country's expansion westward, the Mississippi River has been widely considered a convenient if approximate dividing line between the Eastern, Southern, and Midwestern United States, and the Western United States. This is exemplified by the Gateway Arch in St. Louis and the phrase "Trans-Mississippi" as used in the name of the Trans-Mississippi Exposition.

It is common to qualify a regionally superlative landmark in relation to it, such as "the highest peak east of the Mississippi" or "the oldest city west of the Mississippi". The FCC also uses it as the dividing line for broadcast call-signs, which begin with W to the east and K to the west, mixing together in media markets along the river.