If Tecumseh had his way, American expansion would have ended at the Ohio River. The Shawnee leader believed that the lands belonged to all the tribes, together. He opposed any treaties that transferred territory to the whites. The U.S. disagreed, and so did many tribes.
After the Treaty of Greenville basically gave the U.S. the rights to Ohio in 1795, Tecumseh started putting together an Indian coalition to fight the incursions. It was a formidable effort—until the Shawnee and their allies were defeated at the Battle of Tippecanoe in 1811, ending the coalition.