The difficult and interesting questions relating to the origin, civilisation and fate of the Mound Builders, have been the subjects of frequent investigations and of numerous theories. They appear to have inhabited Ohio for many centuries. CHAPTER VI. The burning of the Steamer Stonewall. — Indian Mounds and Earthworks at Cahokia. — Confluence of the Mississippi and Missouri. — Sacs and Foxes. — Education of Indians. — Nauvoo. — Winona. — Sioux Encampment. — Ancient Mounds near St. Paul’s. — The Sioux War in Minnesota. — Note upon the Ogallalas. Upon the conclusion of a navigation of the waters of the Ohio, which had extended over a distance exceeding nine hundred miles, we arrived at the mouth of that river, and proceeded on our course up the Mississippi. Evening was approaching when we saw a large steamer called the Stonewall, passing us on her way to New Orleans, crowded with passengers happily unaware of the terrible nature of their impending fate, and of the event about to happen before nightfall. At sunset, all those who were on board of our vessel, were assembled upon the upper deck, watching the unusual brilliancy of the reflections upon the water, and the vivid colouring of the clouds gathering round the setting sun. We then supposed these effects to be caused by the haze sometimes observed in the atmosphere during that beautiful season towards the close of the year, which has been given the name of the Indian summer. We were ignorant of the conflagration that was taking place lower down the river, or we might have surmised that the glowing tints were possibly caused by the smoke and flames rising from the burning of the steamer we had seen earlier in the afternoon. We were afterwards informed that news had been received, that a disastrous fire had occurred on board the Stonewall shortly after we passed her, and the flames spread with such rapidity, that, although she was close to the river banks, only thirty-five out of two hundred and forty passengers were saved. The accident was caused by the carelessness of a man, who, when lighting his pipe, accidentally set fire to a quantity of hay that was carried between the upper decks as cargo. It was usual to protect the hay when embarked in this manner, by covering it with a tarpaulin, but through some inattention this precaution had been neglected. The Stonewall was burnt to the water’s edge. As we drew near to St. Louis, we passed the wide low plains upon which is situated the great Cahokia Mound. As it was my purpose to make an expedition to that part of Illinois before proceeding to the upper part of the Mississippi Valley, I went there a few days after we had landed from the steamer.