In the sequence of cultural stages first proposed for the archaeology of the Americas by Gordon Willey and Philip Phillips in 1958, the Lithic stage was the earliest period of human occupation in the Americas, as post-glacial hunter gatherers spread through the Americas. The stage derived its name from the first appearance of Lithic flaked stone tools. The term Paleo-Indian is an alternative, generally indicating much the same period. The Lithic stage was followed by the Archaic stage.