Final answer:
Tecumseh sought to unite Native American tribes against U.S. expansion, but his vision was ultimately not achieved due to the defeat at the Battle of Tippecanoe and his own death at the Battle of the Thames.
Step-by-step explanation:
Tecumseh, a prominent Shawnee war chief, had a clear agenda to preserve Native American lands and culture by forming a confederation among the various tribes to oppose the encroachment and policies of the United States. He became fiercely opposed to the sale of Indian land without the consent of all the tribes, a view which was in stark contrast to governmental practices of that time. Tecumseh's brother, Tenskwatawa, known as the Prophet, urged a return to traditional native customs and the rejection of American influences such as alcohol. Together, they represented a unification of military and spiritual resistance against American expansion.
However, while Tecumseh was away attempting to expand their alliance, his brother engaged in the Battle of Tippecanoe against forces led by William Henry Harrison and was defeated, which led to discouragement and dissolution among the confederated tribes. Tecumseh's alliance was further weakened after his death at the Battle of the Thames in 1813, which signified that his agenda to create a strong Indian confederation ultimately was not achieved. The loss of his leadership led most tribes to retreat, and British forces, having lost their key ally, experienced setbacks as well.