In what chronological order did the great civilizations of mexico , central america and south america appear?

In Mexico the Olmec is considered the first significant civilization who are believed to have lived in the present day Veracruz and Tabasco. Following Olmec was the great Mayan civilization who occupied a large are including southeastern Mexico and Central America. Aztec a well-documented culture also known as Mexica culture.  And lastly the Inca or Incan Empire in South America which is probably the largest empire in early 16th century. 

answer; ///(1) blank; henry clay; (2) blank; secretary of state; (c)is your answer; ///good luck

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.