the fourth chickasaw bluff was the site of the french fort assumption, used as a base against the chickasaw in the abortive campaign of 1739. the chickasaw bluff secured memphis from river floods, while a rare shelf of sandstone below provided a secure boat landing, making this the "only site for a commercial mart" between the ohio river and vicksburg, mississippi. this location was also the meeting place of d'artaguette, chicagou and de vincennes before their ill-fated 1736 attack against the chickasaw.