The Mississippi carries the waters from nearly two thirds of the United States out to the Gulf of Mexico. The great exploration of North America by Europeans that took place over less than five hundred years, happened quickly and at a time when there were no railways or good roads. So using rivers was a natural choice. The rivers in the east of America are short and have steep courses, so they were no use for carrying people and cargoes. The rivers in the west do the same. So, the only river which stretches out its wide branches into the heart of North America is the Mississippi, and it was reached from the south.

The native Americans knew all about the river. But their interests were in hunting animals and they travelled light. However, the Europeans were interested in moving goods and in getting to places quickly. So it was the Europeans who first put up cities by the river and who used the river as a mighty canal. There were two kinds of craft on these rivers. The first were rafts. These were made of bundles of logs from forests cut down in the mountains on the edges of the Mississippi basin. They were simply strapped together and allowed to float down with the current. They were even big enough to have huts on for the steersmen.

The other kind of craft were the river boats, or ‘river queens’ as they were known. Because the river is quite shallow, they were paddle steamers. They were the workhorses of the river and they allowed the whole drainage basin to be developed in less than a century.

It’s not easy to find the source of a large river, especially one with many branches. But people largely agree that the source is up on the plains and lakes of Minnesota near the border with Canada.

The Western headwaters of the Mississippi come together to form a river almost as mighty as the Mississippi itself. This river is the Missouri, and its source is in the high snow-clad Rocky Mountains. The most famous of the sources of the Missouri is the Yellowstone River. It begins with steaming hot water from geysers, including the famous geyser known as Old Faithful.

Quite soon the branches of the Missouri, including rivers like the Yellowstone and the Platte, gather together to make a mighty river which flows over the plains to join the Mississippi at St. Louis. Here it flows over the dry grasslands called the Great Plains. In spring the snow often melts quickly and this makes the Missouri liable to flooding.

The Mississippi and its main tributary, the Missouri, meet where St. Louis now stands. Close to this city was the place where most emigrants set out on their trek to find new farmland in the nineteenth century. From near here, west, lay the Oregon Trail.

St. Louis was founded in 1764 when the Midwest was a colony of France known as Louisiana. St. Louis was sold to the United States in 1803. Shortly after the purchase, the Lewis and Clark Expedition left St. Louis in May 1804, reaching the Pacific Ocean in summer 1805, and returning on September 23, 1806. Both Lewis and Clark lived in St. Louis after the expedition. Many other explorers, settlers, and trappers took much the same route to the west. Steamboats first arrived from New Orleans in 1817. Immigrants from Ireland and Germany arrived in St. Louis from the 1840s.

The Mississippi is a powerful river that can also become shallow in springtime before the floods arrive from the mountains. In some places it also forms into huge loops called meanders. All of this makes it difficult to use the river. As a result, many changes to its course have been made over the years. The depth of water has also been kept steady by the building of huge barrages, or dams across the river. These make the river upstream of the barrage into a kind of lake. Giant locks allow boats to get past each barrage. Some of barrages on the Mississippi river system are used to generate hydro-electric power. Many more are planned.

The branches of the Mississippi that rise in the east are generally smaller than those from the west. They all rise on the western slopes of the Appalachian Mountains. One of the biggest rivers to begin on the slopes of the Appalachians is the Ohio.

Another important eastern river is the Tennessee. It also begins in the Appalachians among dense forests where coal is found. The Tennessee valley was once farmed by many poor farmers. They did not know how to farm the land properly, and when heavy rains came, the soil was washed away. The Tennessee became famous for its floods and poor people. To hold back the floods many dams were built by the Tennessee Valley Authority (TVA) and farmers moved elsewhere. Much of the land was reforested, or farmed in more environmentally-friendly ways. The dams are an important source of hydro-electric power.

New Orleans is the most southerly and the first city to be settled by Europeans. It was named by the French colonists after the French city of Orleans. The early city was founded on riverside banks called levees. All of the land around the levees (and sometimes the levees themselves) are liable to flooding. The city has grown off the levees onto land that is very close to sea level and has to be protected by earth walls (dykes).

The Mississippi carries a huge load of mud and silt. The mud is what makes the river water look brown. When it finally reaches the Gulf of Mexico, it is some 2,320mi (3,730km) from the source. Here the swift river waters get mixed up in the seawater and much of the silt settles out to build the finger of land that we call the delta. You can see it in the picture above. You can also see how the sea currents then set to work on some of the mud and silt, moving it along the shore.