THE WESTWARD EXPANSION Introduction The Westward Expansion has often been regarded as the central theme of American history, down to the end of the19th century and as the main factor in the shaping of American history. As Frederick Jackson Turner says, the greatest force or influence in shaping American democracy and society had been that there was so much free land in America and this profoundly affected American society. Motives After the revolution, the winning of independence opened up the Western country and was hence followed by a steady ....