In The Pioneers Philip Sparke salutes the bicentenary of an expedition by two all time American heroes - Meriwether Lewis and William Clark. They were commissioned by US President Thomas Jefferson to find the headwaters of the Missouri and a route to the Pacific following the Louisiana Purchase, which doubled the size of the USA. They set out as the ‘Corps of Discovery’ from Louisville, Kentucky, in May 1804 and not only did they succeed in reaching the Pacific through hostile territory, but als...