The history of Ontario covers the period from the arrival of Paleo-Indians thousands of years ago to the present day. The lands that make up present-day Ontario, the most populous province of Canada as of the early 21st century have been inhabited for millennia by groups of Aboriginal people, with French and British exploration and colonization commencing in the 17th century. Before the arrival of Europeans, the region was inhabited both by Algonquian (Ojibwa, Cree and Algonquin) and Iroquoian (Iroquois, Petun and Huron) tribes. French explorer Étienne Brûlé surveyed part of the area in 1610–12. The English explorer Henry Hudson sailed into Hudson Bay in 1611 and claimed the area for England, but Samuel de Champlain reached Lake Huron in 1615. In their effort to secure the North American fur trade, the English / British and the French established a number of fur trading forts in Ontario during the 17th and 18th centuries; with the former establishing a number of forts around Hudson Bay, and the latter establishing forts throughout the Pays d'en Haut region. Control over the area remained contested until the end of the Seven Years' War, when the 1763 Treaty of Paris awarded the colony of New France to the British. Following the American Revolutionary War, the province saw an influx of loyalist settle the area. In response to the influx of loyalist refugees, the Constitutional Act of 1791 was enacted, splitting the colony of Quebec into Lower Canada (present day southern Quebec) and Upper Canada (present day southern Ontario). The Canadas were reunited as the Province of Canada by the Act of Union 1840. On July 1, 1867, the Province of Canada, New Brunswick, and Nova Scotia were united to form a single federation. The Province of Canada was split into two provinces at Confederation, with the area east of the Ottawa River forming Quebec, and the area west of the river forming Ontario. Woodland period The Woodland period directly followed the Archaic period. It saw the introduction of ceramics in the Early Woodland period, horticultural experimentation with different crops (notably maize, or corn) as well as elaborate burial ceremonialism during the Middle Woodland, and the emergence of agriculture and village settlements by the Late Woodland. Especially by the Late Woodland, there was a divergence between northern and southern Ontario, as agriculture only took place in southern Ontario. However, northern Ontario saw significant changes in pottery