Final answer:
The main cause of contention between Tecumseh and William Henry Harrison was land disputes.
Step-by-step explanation:
The main cause of contention between Tecumseh and William Henry Harrison was land disputes.
Tecumseh argued that no single tribe owned the land, so no tribe could sell it without the agreement of all Indian tribes. However, Harrison was successful in negotiating the sale of the land by getting several tribes to agree to it. This disagreement over land ownership and the sale of land led to tensions between Tecumseh and Harrison.