Explain how manifest destiny directed political, economic, and cultural policies during the 19th century?

Manifest Destiny. beleif held in 19th century by many Americans that U. S. was destined to (meant to) span from Atlantic Ocean to Pacific Ocean, spreading its culture and democracy; belief had political, economic, and social roots:growth in U. S. economy increased demand for (and value of) farmland, ranches, and furs; the cotton gin increased the area in which cotton could be grown profitably; the discovery of gold in California attracted 80,000 people in1849