The history of the mines of Dubuque is brief and simple. In 1780, a discovery of lead ore was made by the wife of Peosta, a Fox Indian of Aquoqua's Village. This gave the hint for explorations, which resulted in extensive discoveries. The lands were formally granted by the Indians to Julien Dubuque, at a council held at Prairie du Chien in 1788, by virtue of which he permanently settled on them, erected buildings and furnaces, and continued to work them until 1810. In 1796, he received a confirmation of his grant from Carondelet, the governor of Louisiana, in which they are called "the mines of Spain." By a stone monument which stands on a hill near the mines, Dubuque died on the 24th March, 1810, aged forty-five years and six months. After his death, the Indians burnt down his house and fences--he leaving, I believe, no family[116]--and erased every vestige of civilized life; and they have since revoked, or at least denied the grant, and appear to set a very high value on the mines. Dubuque's claim was assigned to his creditors, by whom it was presented to the commissioners for deciding on land titles, in 1806. By a majority of the board it was determined to be valid, in which condition it was reported to Washington for final action. At this stage of the investigation, Mr. Gallatin, who was then Secretary of the Treasury, made a report on the subject, clearly stating the facts, and coming to the conclusion that it was not a perfect title, stating that no patent had ever been issued for it, at New Orleans, the seat of the Spanish authority, from which transcripts of the records of all grants had been transmitted to the Treasury.[117] [116] There is believed to be no instance, in America, where the Indians have disannulled grants or privileges to persons settling among them, and leaving families founded on the Indian element. [117] For the facts in this case, see _Collection of Land Laws of the United States_, printed at Washington, 1817. On the arrival of Lieut. Pike at Mr. Dubuque's on the 1st of September, 1805, he endeavored to obtain information necessary to judge of the value and extent and the nature of the grant of the mines; but he was not able to visit them. To the inquiries which he addressed to Mr. Dubuque on the subject, the latter replied in writing that a copy of the grant was filed at the proper office in St. Louis, which would show its date, together with the date of its confirmation by the Spanish authority, and the extent of the grant to him. He states the mine to be twenty-seven or twenty-eight leagues long, and from one to three leagues broad. He represents the per centum of metal to be yielded from the ore to be seventy-five, and the quantity smelted per annum at from 20,000 to 40,000 pounds. He stated that the whole product was cast into pig lead, and that there were no other metals at the mines but copper, of the value of which he could not judge.