Final answer:
Tecumseh, a Shawnee war chief, led the Indian Confederation in the West. The unification of Native American tribes into the Western Confederacy was to resist American expansion and to maintain control over their territories. Conflicts like the Northwest Indian War ensued, culminating in the Treaty of Greenville.
Step-by-step explanation:
The leader of the Indian Confederation in the West was Tecumseh, a Shawnee war chief. He aimed to unite various Native American tribes to resist the American intrusion into their lands. The primary motive behind the unification of these tribes into what became known as the Western Confederacy was to protect and retain control over their ancestral lands. This movement was reignited by Tecumseh along with his brother Tenskwatawa, a prophet who advocated for the revival of native traditions and the rejection of Anglo-American influence. After the American Revolution, the United States government moved to assert control over land in western New York and Pennsylvania. This expansion into Native American territories led to conflicts, including the Northwest Indian War from 1785 to 1795. The Native American defeat at this war resulted in the Treaty of Greenville, where the U.S. gained dominion over Ohio lands. The Western Confederacy's resistance highlighted the broader struggle of Native American nations, such as the Sioux and Apache, who were skilled in warfare and determined to protect their homelands against frontier expansion.