According to Sugden (1997), Tecumseh had made a "serious mistake" by informing Harrison he would be absent from Prophetstown for an extended time. Harrison wrote that Tecumseh's absence "affords a most favorable opportunity for breaking up his Confederacy." In September 1811, Harrison marched toward Prophetstown with about 1,000 men. In the pre-dawn hours on November 7, warriors from Prophetstown launched a surprise attack on Harrison's camp, initiating the Battle of Tippecanoe. Harrison's men held their ground, after which the Prophet's warriors withdrew and evacuated Prophetstown. The Americans burned the village the following day and returned to Vincennes.