Like many other Native Tribes, the Quapaw experienced a severe population reduction due to European diseases. The Native Tribes were susceptible to many types of diseases because they had never been exposed to them (therefore had never built a resistance to them). Also, they were all genetically very similar and had similar immune systems. So, when the diseases hit, the Natives were highly affected by them. Some estimates say that there was a 95% drop in population all over the continent. In other words, for every 100 Native Americans, only 5 survived. In the late 1600s, the Quapaw were estimated to have a population greater than 5000. Over a period of 80 years, their population had dropped to 700 due to a smallpox epidemic in 1699. Sadly, because of this massive population drop, much of early Quapaw history and lore, which was passed on orally, died with its storytellers. Even today the Quapaw tribe doesn't have as many members as it did in the early 1600s. By 1720, the Quapaw had abandoned one of their villages because there simply were not enough people to maintain all four of their original villages.
The French were the first Europeans to contact the Quapaw. They had colonies in the northeastern part of North America and were interested in finding a trade route to the Pacific Ocean. Two Frenchmen, Jaquis Marquette and Louis Joliet, followed the Mississippi River in 1673, hoping that it might lead to the Pacific Ocean. They stopped at a Quapaw village, where they learned that the Mississippi flowed into the Gulf of Mexico. They returned home after spending some time with the hospitable Quapaw.
In 1682, Robert De La Salle and Henri De Tonti were the next Frenchmen to contact the Quapaw. When they arrived at a Quapaw town, they spoke Illinois (an Algonkian language, the same language family spoken by tribes near French colonies in the northeast) to an Illinois captive and asked who the people in the town were. The captive responded in Algonkian that these people were the "Akansa." This was the origin of the name of the state of Arkansas.
La Salle, interested in having an ally in an area he felt might become important in the struggle for dominance of the continent, established relations with the Quapaw. The Quapaw were happy to become allies with a powerful colonizing nation who could supply them with weapons. The Quapaw were faithful to their French allies in the tumultuous century that followed, when the major Europeans powers were vying for control of the continent. The European powers often used their Native allies to attack both their enemies and tribes allied with them. This struggle ended with an English victory over the French in the Seven Years' War (also known as the French-Indian War), when France ceded all land East of the Mississippi to the Spanish (1762). For all intents and purposes, the French, whom the Quapaw had faithfully aided, were no longer a presence in the Americas.