Father Marquette remained in the mission of St. Francois Xavier through the summer of 1674, and late in the fall started on his journey back to Kaskaskia. The escort consisted of two Frenchmen and some Indians. They reached the Chicago portage in the midst of discouraging circumstances. The weather was severe and Father Marquette, sick unto death, was unable to proceed further. On the banks of the Chicago River they built some huts and here the party remained till spring. During the winter Father Marquette did not suffer for want of attention, for he was visited by a number of Indians and by at least two prominent Frenchmen. By the last of March he was able to travel. He reached the Kaskaskia village Monday, April 8, 1675. He was received with great joy by the Indians. He established the mission of the Immaculate Conception of the Blessed Virgin. Seeing he could not possibly live long, he returned to St. Ignace by way of the Kankakee portage. He never lived to reach Mackinaw. He died the 18th of May, 1675. This expedition by Marquette and Joliet on the Illinois had carried the lilies of France nearly to the Gulf of Mexico. The Indians in the great plains between the Great Lakes and the Gulf had been visited and the resources of the country noted. There remained but a slight strip of territory over which the banner of France had not floated, from the Gulf of St. Lawrence to the Gulf of Mexico. If this short distance were explored, then the French government would have completely surrounded the English colonies in North America.
Source: A Standard History of Champaign County, Illinois, by J. R. Stewart, published by The Lewis Publishing Company, Chicago And New York, 1918.