The publication of the valuable works of Squier and Davis, of Dr. Lapham and those of Mr. Squier alone, in which the remains of these regions are described, was like a revelation which brought to light the wonders of an entombed civilization.[7] In treating of the mounds geographically, we find no evidences of this people having reached the Atlantic seaboard, unless we except the great shell-heaps found in various localities on the coast, and of which we will speak further on. It is true that in South Carolina a few vestiges of their residence are found on the Wateree River near Camden, and in the mountainous regions of North Carolina,[8] where they wrought mica mines for the mineral which they prized as precious, and which so often accompanies the remains of their dead. No _authentic_ remains of the Mound-Builders are found in the New England States, nor even in the State of New York. In the former, we have an isolated mound in the valley of the Kennebec in Maine, and dim outlines of enclosures near Sanborn and Concord in New Hampshire, but there is no certainty of their being the work of this people.[9] In the latter, it was at first supposed that the remains found in the western portion of the State were uniform in their plan of construction with the works of the Ohio valley; but Mr. Squier pronounces them to be purely the work of Red Indians. This conclusion should not be viewed as final, even though Cusick’s vague statement (in _Schoolcraft_, vol. v) that the Iroquois “were compelled to build fortifications in order to save themselves from the devouring monsters” lends it an air of plausibility. Either people may have been their builders. Col. Whittlesey would assign these fort-like structures, differing from the more southern enclosures in that they were surrounded by trenches on their outside, while the latter uniformly have the trench on the inside of the enclosure, to a people anterior to the Red Indian and perhaps contemporaneous with the Mound-builders, but distinct from either.[10] A quite reasonable view is that of Dr. Foster, that they are the _frontier_ works of the Mound-builders, adapted to the purposes of defence against the sudden irruptions of hostile tribes. He remarks, “If our country were to become a desolation, the future antiquary would find the sea-coast studded with fortifications of a complex form, and as he penetrated to the interior they would disappear altogether.”[11] It is probable that these defences belong to the last period of the Mound-builders’ residence on the lakes, and were erected when the more warlike peoples of the North who drove them from their cities first made their appearance. Passing along the boundary of the Mound-builders’ territory towards the west, we find the great lakes in all cases to have served as its limit on the north. Mr. Henry Gillman has described in several publications[12] his exploration of mounds in Michigan and the lakes.