James Madison took over as president in 1808 after serving as Thomas Jefferson's secretary of state. In 1811, tensions increased as Britain continued attacking American ships, leading Madison to cut off trade. Meanwhile, the ongoing conflict between Native Americans and settlers in the Ohio Valley was exacerbated by British arms supplies to tribes like the Shawnee, led by Tecumseh. This resulted in the 1810 Battle of Tippecanoe. Mounting anti-British sentiment, especially in the West and South, led to calls for war by the War Hawks faction. In 1812, Madison asked Congress to declare war on Britain.