The fame of Clark's deeds and the terror of his prowess spread to the southern Indians, and the British at Natchez trembled lest they should share the fate that had come on Kaskaskia and Vincennes. [Footnote: State Department MSS. [Intercepted Letters], No. 51, Vol. II., pp. 17 and 45. Letter of James Colbert, a half-breed in the British interest, resident at that time among the Chickasaws, May 25, 1779, etc.] Flat-boats from the Illinois went down to New Orleans, and keel-boats returned from that city with arms and munitions, or were sent up to Pittsburg [Footnote: The history of the early navigation of the Ohio and Mississippi begins many years before the birth of any of our western pioneers, when the French went up and down them. Long before the Revolutionary war occasional hunters, in dug-outs, or settlers going to Natchez in flat-boats, descended these rivers, and from Pittsburg craft were sent to New Orleans to open negotiations with the Spaniards as soon as hostilities broke out; and ammunition was procured from New Orleans as soon as Independence was declared.]; and the following spring Clark built a fort on the east bank of the Mississippi below the Ohio. [Footnote: In lat. 36° 30'; it was named Fort Jefferson. Jefferson MSS., 1st Series, Vol. 19. Clark's letter.] It was in the Chickasaw territory, and these warlike Indians soon assaulted it, making a determined effort to take it by storm, and though they were repulsed with very heavy slaughter, yet, to purchase their neutrality, the Americans were glad to abandon the fort. Clark Moves to the Falls of Ohio. Clark himself, towards the end of 1779, took up his abode at the Falls of the Ohio, where he served in some sort as a shield both for the Illinois and for Kentucky, and from whence he hoped some day to march against Detroit. This was his darling scheme, which he never ceased to cherish. Through no fault of his own, the day never came when he could put it in execution.