Where is the Mississippi River the second-longest 
	river?
	A: North America, second only to the Hudson Bay drainage system.
What is its traditional source?
	A: Lake Itasca in northern Minnesota.
It flows generally south for how many miles?
	A:  2,340 (3,770 km).
Where does it flow to?
	A: The Mississippi River Delta in the Gulf of Mexico. 
With its many tributaries, the Mississippi's watershed 
	drains all or parts of how many U.S. states?
	A: 32.
The Mississippi ranks as the thirteenth-largest river 
	in the world by what?
	A: Discharge. 
The river either borders or passes through what states?
	A: Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, 
	Tennessee, 
	Arkansas, Mississippi, and Louisiana.
Native Americans have lived along the Mississippi River 
	and its tributaries for how long?
	A: Thousands of years. 
Most were hunter-gatherers, but some, such as the Mound 
	Builders, formed what?
	A: Prolific agricultural and urban civilizations.
The arrival of Europeans in the 16th century changed 
	the native way of life as what?
	A: The first explorers, then settlers, ventured into the basin in increasing 
	numbers.
The river served first as a barrier, forming borders 
	for what?
	A: New Spain, New France, and the early United States.
Formed from thick layers of the river's silt deposits, 
	the Mississippi embayment is what?
	A: One of the most fertile regions of the United States.
Steamboats were widely used in the 19th and early 20th 
	centuries to ship what?
	A: Agricultural and industrial goods. 
During the American Civil War, the Mississippi's 
	capture by Union forces marked what?
	A: A turning point towards victory, due to the river's strategic importance 
	to the Confederate war effort.
Because of the substantial growth of cities and the 
	larger ships and barges that replaced steamboats, the first decades of the 
	20th century saw the construction of massive engineering works such as what?
	A: Levees, locks and dams, often built in combination. 
A major focus of this work has been to prevent the 
	lower Mississippi from shifting into the channel of the Atchafalaya River 
	and bypassing what?
	A: New Orleans.
Since the 20th century, the Mississippi River has also 
	experienced what?
	A: Major pollution and environmental problems.
It has elevated nutrient and chemical levels from 
	agricultural runoff, the primary contributor to what?
	A: The Gulf of Mexico dead zone.
From its origin at Lake Itasca to St. Louis, Missouri, 
	the waterway's flow is moderated by how many dams?
	A: 43.
Fourteen of these dams are located above Minneapolis in 
	the headwaters region and serve multiple purposes, including what?
	A: Power generation and recreation. 
The remaining 29 dams, beginning in downtown 
	Minneapolis, all contain what?
	A: Locks and were constructed to improve commercial navigation of the upper 
	river.
Beginning just below Saint Paul, Minnesota, and 
	continuing throughout the upper and lower river, the Mississippi is further 
	controlled by what?
	A: Thousands of Wing Dikes that moderate the river's flow in order to 
	maintain an open navigation channel and prevent the river from eroding its 
	banks.