Father Marquette, a Jesuit priest, and Louis Jolliet, a French explorer are credited as the first two white men to lay eyes on the land that would be called Missouri while travelling south on the Mississippi River. According to Marquette's journal---
….we heard the noise of a rapid, into which we were about to run. I have seen nothing more dreadful. An accumulation of large and entire trees, branches, and floating islands, was issuing from the mouth of the river Pekistanoui [Missouri], with such impetuosity that we could not without great danger risk passing through it. So great was the agitation that the water was very muddy, and could not become clear.
Pekitanoui is a river of considerable size, coming from the northwest, from a great distance; and it discharges into the Mississippi. There are many villages of savages along this river, and I hope by its means to discover the Vermillion or California Sea. Judging from the direction of the course of the Mississippi, if it continues the same way, we think that it discharges into the Mexican Gulf. It would be a great advantage to find the river leading to the Southern Sea, toward California; and, as I have said, this is what I hope to do by means of the Pekitanoui, according to the reports made to me by the savages. From them I have learned that, by ascending this river for five or six days, one reaches a fine prairie, twenty or thirty leagues long. This must be crossed in a northwesterly direction, and it terminates at another small river, on which one may embark, for it is not very difficult to transport canoes through so fine a country as that prairie. This second river flows toward the southwest for ten or fifteen leagues, after which it enters a lake, small and deep, which flows toward the west, where it falls into the sea. I have hardly any doubt that it is the Vermillion Sea, and I do not despair of discovering it some day, if God grant me the grace and the health to do so, in order that I may preach the Gospel to all the peoples of this new world who have so long grovelled in the darkness of infidelity.
Father Marquette wasn't the only man with aspirations to find a water route to the West. Over one hundred and thirty years later President Jefferson would send Lewis and Clark and the Corps of Discovery up the Missouri River in search of the same goal. The most famous landmark in Missouri—the St. Louis Arch commemorates Jefferson's vision and Missouri's role as a "Gateway to the West." Missouri was the starting point for both the Sante Fe and Oregon Trails. The starting point for the famous but short-lived Pony Express was St. Joseph, Missouri.
Along with Western Expansion, a great overlap between Missouri and United States history is the issue of slavery. Missouri territory wanted to form a state government and seek statehood but that would have thrown off the balance of power between slave-holding and free states. In 1820, the Missouri Compromise allowed the territory to form a government and write a constitution but prohibitted slavery in any of the origianl Lousiana territory north of the 36 30' parallel. Later, this legislation was declared unconstitutional by the Supreme Court in the Dred Scot case, stating that the congress didn't not have the authority to prohibit slavery in U.S. territories. (Incidently, even though the steps of the Old Courthouse in St. Louis was often the site of slave auctions, a jury there originally found in favor of the Scots' freedom).
[caption id="" align="aligncenter" width="547" caption="The Old Courthouse"][/caption]
During the Civil War Missouri remained loyal to the Union although it continued to allow slavery. This border state was truly the site of brother fighting against brother. More that 100 battles or skirmishes took place in the state--making it the third most active state after Virginia and Tennessee.