Fort Ticonderoga (), formerly Fort Carillon, is a large 18th-century star fort built by the French at a narrows near the south end of Lake Champlain, in northern New York, in the United States. It was constructed by Canadian-born French military engineer Michel Chartier de Lotbinire, Marquis de Lotbinire between October 1755 and 1757, during the action in the "North American theater" of the Seven Years' War, often referred to in the US as the French and Indian War. The fort was of strategic importance during the 18th-century colonial conflicts between Great Britain and France, and again played an important role during the Revolutionary War.

The site controlled a river portage alongside the mouth of the rapids-infested La Chute River, in the 3.5 miles (5.6 km) between Lake Champlain and Lake George. It was thus strategically placed for the competition over trade routes between the British-controlled Hudson River Valley and the French-controlled Saint Lawrence River Valley.

The terrain amplified the importance of the site. Both lakes were long and narrow and oriented northsouth, as were the many ridge lines of the Appalachian Mountains, which extended as far south as Georgia. The mountains created nearly impassable terrains to the east and west of the Great Appalachian Valley that the site commanded.

The name "Ticonderoga" comes from the Iroquois word tekontar:ken, meaning "it is at the junction of two waterways".During the 1758 Battle of Carillon, 4,000 French defenders were able to repel an attack by 16,000 British troops near the fort. In 1759, the British returned and drove a token French garrison from the fort. During the Revolutionary War, when the British controlled the fort, it was attacked on May 10, 1775, in the Capture of Fort Ticonderoga by the Green Mountain Boys and other state militia under the command of Ethan Allen and Benedict Arnold, who captured it in the surprise attack. Cannons taken from the fort were transported to Boston to lift its siege by the British, who evacuated the city in March 1776. The Americans held the fort until June 1777, when British forces under General John Burgoyne occupied high ground above it; the threat resulted in the Continental Army troops being withdrawn from the fort and its surrounding defenses. The only direct attack on the fort during the Revolution took place in September 1777, when John Brown led 500 Americans in an unsuccessful attempt to capture the fort from about 100 British defenders.

The British abandoned the fort after the failure of the Saratoga campaign, and it ceased to be of military value after 1781. After gaining independence, the United States allowed the fort to fall into ruin; local residents stripped it of much of its usable materials. Purchased by a private family in 1820, it became a stop on tourist routes of the area. Early in the 20th century, its private owners restored the fort. A foundation, the Fort Ticonderoga Association, now operates the fort as a tourist attraction, museum, and research center.

The Beaver Wars (Mohawk: Tsianì kayonkwere), also known as the Iroquois Wars or the French and Iroquois Wars (French: Guerres franco-iroquoises), encompass a series of conflicts fought intermittently during the 17th century in North America throughout the Saint Lawrence River valley in Canada and the lower Great Lakes region which pitted the Iroquois against the Hurons, northern Algonquians and their French allies.

As a result of this conflict, the Iroquois destroyed several confederacies and tribes through warfare: the Hurons or Wendat, Erie, Neutral, Wenro, Tionontate, Susquehannock, Mahican and northern Algonquins whom they defeated and dispersed, some fleeing to neighboring peoples and others assimilated, routed and killed.

The Iroquois sought to expand their territory and to monopolize the fur trade with European markets. They originally were a confederacy of the Mohawk, Oneida, Onondaga, Cayuga, and Seneca tribes inhabiting the lands in what is now Upstate New York along the shores of Lake Ontario east to Lake Champlain and Lake George on the Hudson river, and the lower-estuary of the Saint Lawrence River. The Iroquois Confederation led by the Mohawks mobilized against the largely Algonquian-speaking tribes and Iroquoian-speaking Huron and related tribes of the Great Lakes region. The Iroquois were supplied with arms by their Dutch and English trading partners; the Algonquians and Hurons were backed by the French, their chief trading partner.

The Iroquois effectively destroyed several large tribal confederacies, including the Mohicans, Huron (Wyandot), Neutral, Erie, Susquehannock (Conestoga), and northern Algonquins, with the extreme brutality and exterminatory nature of the mode of warfare practised by the Iroquois causing some historians to label these wars as acts of genocide committed by the Iroquois Confederacy. They became dominant in the region and enlarged their territory, realigning the American tribal geography. The Iroquois gained control of the New England frontier and Ohio River valley lands as hunting ground from about 1670 onward.

Both Algonquian and Iroquoian societies were greatly disrupted by these wars. The conflict subsided when the Iroquois lost their Dutch allies in the colony of New Netherland after the English took it over in 1664, along with Fort Amsterdam and the town of New Amsterdam on the island of Manhattan. The French then attempted to gain the Iroquois as an ally against the English, but the Iroquois refused to break their alliance, and frequently fought against the French in the 18th-century. The Anglo-Iroquois alliance would reach its zenith during the French and Indian War of 1754, which saw the French being largely expelled from North America.

The wars and subsequent killings of beavers were devastating for the local beaver population. The natural ecosystems that came to rely on the beavers for dams, water and other vital needs were also devastated leading to ecological destruction, environmental change, and drought in certain areas. Following this beaver populations in North America would take centuries to recover in some areas, while others would never recover.