Tecumseh returned to Amherstburg in April 1813. Meanwhile, the Americans, having suffered defeat at the Battle of Frenchtown in January 1813, were pushing back toward Detroit under the command of William Henry Harrison. Tecumseh and Roundhead led about 1,200 warriors to Fort Meigs, a recently constructed American fort along the Maumee River in Ohio. The Indians initially saw little action while British forces under General Henry Procter laid siege to the fort. Fighting outside the fort began on May 5 after the arrival of American reinforcements, who attacked the British gun batteries. Tecumseh led an attack on an American sortie from the fort, then crossed the river to help defeat a regiment of Kentucky militia. The British and Indians had inflicted heavy casualties on the Americans outside the fort, but failed to capture it. Procter's Canadian militia and many of Tecumseh's warriors left after the battle, so Procter was compelled to lift the siege.