But intermediately between the copper regions of Lake Superior and the ancient southern scenes of native American civilisation, the Mississippi and its great tributaries drain a country remarkable for monuments of a long forgotten past, not less interesting and mysterious than the forsaken mines of Keweenaw and Ontonagon, or Isle Royale. Those great earthworks are ascribed to an extinct race, conveniently known by the name of the Mound-Builders. Careful investigations into their structure and contents prove these builders to have been a people among whom copper was in frequent use, but by them also it was worked only by the hammer. The invaluable service of fire in reducing and smelting ores, moulding metals, and adapting them to greater usefulness by well-proportioned alloys, was unknown; and the investigation and analysis of their cold-wrought tools seem to prove that the source of their copper was the Lake Superior mines. But though the ancient Mound-Builder was thus possessed of little higher metallurgic knowledge than the Indian hunter: he manifested in other respects a capacity for extensive and combined operations, the memorials of which perpetuate his monumental skill and persevering industry in the gigantic earthworks from whence his name is derived. From these we learn that there was a period in America’s unrecorded history, when the valleys of the Mississippi and its tributaries were occupied by a numerous settled population. Alike in physical conformation—so far as very imperfect evidence goes,—and in some of their arts, these Mound-Builders approximated to races of Central and South America, and differed from the Red Indian occupants of their deserted seats. They were not, to all appearance, far advanced in civilisation. Compared with the people of Mexico or Central America when first seen by the Spaniards, their social and intellectual development was probably rudimentary. But they had advanced beyond that stage in which it is possible for a people to continue unprogressive. The initial steps of civilisation had been inaugurated; and the difference between them and the civilised Mexicans is less striking than the contrast which the evidences of their settled condition, and the proofs of extensive co-operation in their numerous earthworks supply, when compared with all that pertains to the tribes by whom the American forests and prairies have been exclusively occupied during the centuries since Columbus.