Final answer:
The advice in the excerpt from Horace Greeley reflects the influence of Manifest Destiny, which was a belief that Americans had a divine right and responsibility to settle the West with democratic values.
Step-by-step explanation:
The advice in the excerpt from Horace Greeley reflects the influence of Manifest Destiny. Manifest Destiny was a widely held belief in the 19th century that Americans had a divine right and responsibility to settle the West with Protestant democratic values. Horace Greeley encouraged Americans to fulfill this dream by urging young men to go west. This idea of expanding the boundaries of the United States and spreading freedom aligns with the concept of Manifest Destiny.