In the Book of Mormon, specifically the Book of Ether, the Jaredites are described as the descendants of Jared and his brother. At the time the Tower of Babel was destroyed and the tongues of all nations were confounded, the Lord accedes to the desires of Jared and his brother such that their language, as well as that of their families and friends, was not confounded, and they were granted a land of promise.

According to the narrative, the people were guided by God through the wilderness, and were eventually directed to cross the sea in "barges." (http://scriptures.lds.org/ether/2/16#16)

Ether is the last in the royal line that began with one of the sons of Jared. From the time of the first king to the destruction of the Jaredites, there were only occasional times of peace and prosperity. These times of peace were interrupted by intrigue to the throne, civil war, and the accession of wicked kings. Thus the history of the Jaredites proved the fear of Jared and his brother that a monarchy would lead to captivity.[1] (http://scriptures.lds.org/omni/6/22-23#22)

The Jaredites finally destroyed themselves about the time Lehi and the other refugees from Jerusalem arrived in America (see also Nephites, Lamanites, and Mulekites). A prophecy given (http://scriptures.lds.org/ether/13/20-21#20) by Ether is fulfilled, and the last Jaredite king, Coriantumr, lives both to see the total destruction of his people and the arrival of another people to inherit the land.[2] (http://scriptures.lds.org/omni/1/21#20)

See also Mahonri Moriancumer.