Who is York from The Journals of Lewis and Clark and what is their importance?

York was the name of William Clark's "servant." He was a black slave bequeathed by the captain's father in 1799. Clark and York, who were about the same age, lived together throughout the expedition. The character of York, the first black man to cross the continent north of the Mexican continent, became a part of the legend of the Lewis and Clark expedition. His story and prowess are often embellished by subsequent fiction writers as well as imaginative historians.