Ethnologists now accept the conclusion that the races who built the mounds were pressed to the southward by ruder invaders who came from the North and that the great battles of the conflict between the two were fought in Ohio where the remains of the fortifications erected for defense still remain. On this continent we have, on a smaller scale, a duplication of the struggle which ended in the overthrow of the Roman empire. The great body of these invaders were diverted towards Mexico, where the Toltec empire was overthrown by the Aztecs, soon to be conquered in their turn by the Spaniards under Cortez. But there was no wide difference between the culture of the invaders and the Mound Builders; both were ignorant of the use of metals and both belonged to the Stone Age, although a people capable of such works as the defensive mounds must have been much more than rude hunters. The strategic points they selected are now the sites of our cities and showed ability of no mean order since they constituted successive lines of defense such as would now be adopted under like circumstances.
"Indian Races of Florida,"
Florida Historical Quarterly: Vol. 3:
2, Article 8.
Available at: https://stars.library.ucf.edu/fhq/vol3/iss2/8