In this sweeping survey, Milo Milton Quaife traces the events leading from Chicago's emergence as a key outpost at the edge of the frontier to its establishment as the crossroads of American commerce.   Strategically located at the head of the Great Lakes on the Chicago portage, one of the main highways connecting the Great Lakes-St. Lawrence waterway with the Mississippi River, Chicago was equally valued by explorers, traders, settlers, and governments. Quaife narrates the opening of trade and the course of European exploration, facilitated by the Chicago portage and subsequent construction of the Illinois and Michigan Canal. He profiles the personalities who shaped the early Chicago area, from the French explorers La Salle, Marquette, and Joliet to the ambitious Champlain, who set the course for decades to come by securing for New France the enmity of the Iroquois.   Quaife provides a full description of the Indian trade, which constituted the basis of commerce in the region for the entire period covered by the book, as well as a blow-by-blow account of how old rivalries and alliances between Indian tribes complicated the English and French plans for divvying up the New World. He also describes the conflicts between natives and whites with sympathy and detail on both sides, depicting Indian attacks on white settlements as rationally motivated acts aiming toward specific goals of strategy or revenge.   First published in 1913, Chicago and the Old Northwest, 1673-1835 is one of the earliest works of a man who became one of the premier scholars of his generation. In a new introduction, Chicago historian Perry R. Duis sketches Quaife's long and varied career, his influence on the history profession, and his crusade to prove that a black trader was the first permanent resident of Chicago.