The correct answer is - trade.
The Sumerians engaged in trade with their move of exchanging their surplus food for materials like the copper that they needed to develop their weapons and thus their army forces. This was a very smart move from their side because they managed to use the resource they had in abundance but was scarce in the other surrounding areas so that they take what they need to become stronger and pretty much defend more efficiently from the same people they were engaging in trade with.
The 1948 United States Presidential Election is considered apart from being one of the biggest electoral upsets in American history, the start of an era of great economic prosperity and growth of the United States as a superpower in the land of politics.
After winning the election then President elect Harry S. Truman implemented and oversaw various policies in order to contain and stop the influence of communism around the world which culminated in the entry of the United States in the Korean war.
During this time period President Truman also oversaw the approval of NSC 68, a secret statement of foreign policy. Which sought to increase the defense budget and in turn increase the military prowess of the US and weaken the Soviet Union's influence as much as possible.
The results of the 1948 Presidential Elections also influenced the reform of civil rights in the US, more specifically voting rights and fair employment rights, these reforms also had a key role in ending racial segregation in the armed forces.
Answer:
Fort Defiance was established in 1851 by Col. Edwin V. Sumner to set military presence. The Federal Government banned the Navajos to use or access this area. Consequently, they begun fighting, ending in two attacks: 1856 and 1860. In 1861, the army left Fort Defiance, but Brigadier General James H. Carleton continued fighting the Navajos.