There are existing monuments of an American ancient history which invite study, and most of which might, doubtless, have been studied more successfully in the first part of the sixteenth century, before nearly all the old books of Central America had been destroyed by Spanish fanaticism, than at present. Remains of ancient civilizations, differing to some extent in degree and character, are found in three great sections of the American continent: the west side of South America, between Chili and the first or second degree of north latitude; Central America and Mexico; and the valleys of the Mississippi and the Ohio. These regions have all been explored to some extent--not completely, but sufficiently to show the significance and importance of their archæological remains, most of which were already mysterious antiquities when the continent was discovered by Columbus. I propose to give some account of these antiquities, not for the edification of those already learned in American archæology, but for general readers who have not made the subject a study. My sketches will begin with the Mississippi Valley and the regions connected with it. THE MOUND-BUILDERS--THEIR WORKS. An ancient and unknown people left remains of settled life, and of a certain degree of civilization, in the valleys of the Mississippi and its tributaries. We have no authentic name for them either as a nation or a race; therefore they are called “Mound-Builders,” this name having been suggested by an important class of their works. [Illustration: Fig. 2.--The Great Mound, near Miamisburg.] Prominent among the remains by which we know that such a people once inhabited that region are artificial mounds constructed with intelligence and great labor. Most of them are terraced and truncated pyramids. In shape they are usually square or rectangular, but sometimes hexagonal or octagonal, and the higher mounds appear to have been constructed with winding stairways on the outside leading to their summits. Many of these structures have a close resemblance to the _teocallis_ of Mexico. They differ considerably in size. The great mound at Grave Creek, West Virginia, is 70 feet high and 1000 feet in circumference at the base. A mound in Miamisburg, Ohio, is 68 feet high and 852 feet in circumference. The great truncated pyramid at Cahokia, Illinois, is 700 feet long, 500 wide, and 90 in height. Generally, however, these mounds range from 6 to 30 feet high. In the lower valley of the Mississippi they are usually larger in horizontal extent, with less elevation. Figure 2 represents the great mound near Miamisburg, Ohio, which may be compared with a similar structure at Mayapan, Yucatan (Fig. 34). Figure 3 shows a square mound near Marietta, Ohio. [Illustration: Fig. 3.--Square Mound, near Marietta.]