Iowa began utilizing domesticated plants. The subsequent Woodland period saw an increase on the reliance on agriculture and social complexity, with increased use of mounds, ceramics, and specialized subsistence. During the Late Prehistoric period (beginning about A.D. 900) increased use of maize and social changes led to social flourishing and nucleated settlements. The arrival of European trade goods and diseases in the Protohistoric period led to dramatic population shifts and economic and social upheaval, with the arrival of new tribes and early European explorers and traders. Early Historic Native Americans By 1804, there were a number of Native American groups in Iowa: the Sauk (Sac) and Meskwaki (Fox) on the eastern edge of Iowa along the Mississippi; the Ioway along the bank of the Des Moines River; the Oto, Missouri, and Omaha along the Missouri River, and the Sioux in the Northern and Western parts of the State. Additionally, earlier records indicate the presence of the Illinois in Iowa, though they were nearly gone by the time of the 1804 observations. The total number of these groups in Iowa in 1804 is estimated to be less than 15,000. While these groups generally came initially for food, some of them (e.g., Illinois, Sauk, Meskwaki) immigrated as a result of warfare with other tribes or the French. The early and mid-19th century saw the movement of additional groups of Native Americans into Iowa, such as the Potawatomi and Winnebago, followed by the emigration from Iowa of nearly all Native Americans. The first European or American to make contact with Native Americans in Iowa is generally considered to be the Frenchmen Louis Joliet and Pere Jacques Marquette, though earlier contact by others is possible. They had set out to discover the Mississippi River, and contacted the Illinois on the eastern side of Iowa in 1673. They also were told at that time of the presence of the Sioux along the Missouri. Upon the departure of Joliet and Marquette from the Illinois village, they were accompanied to the riverbank by nearly 600 Illinois, who showed "every possible manifestation of joy," having treated the first Europeans well and offered them peace. Additional exploration by early French, British, and American trappers, traders, explorers, and missionaries informs us of the nature of Native American presence in Iowa from this initial contact in 1673 to the start of settlement by the United States. The Sauk and Meskwaki constituted