How do something become a historic site?

What ARE fallen soldiers? What is the name of the hourglass looking instrument that Christopher Columbus used on his voyage to the new world? What season was it in Japan when Nagasaki was bombed? Why did the pioneers settled in the great plains? What did colonists grow? Where did the Mayan go? Who or what created the Rosetta stone? What is the origin or ethnicity of last name Guiza? What did Romans drink during battles in the Roman Colosseum? What different types of colonies are there? Who was the group of georgians that opposed the stamp act? List 3 sporting events that only occurred at the ancient games and 3 event that only occur at the modern games? Which leadership did the Inca expand quickly under? How did akhenation upset the traditional order? What was the Greek influence on Rome? What types of dresses were worm by the member of jacobins club and how they are different from aristrocrate? What foods were unsuccessfully grown in Jamestown? What were the key characteristics of 19th-century Victorian dresses and how did they reflect the societal norms and values of that era? The warlords of China the samurai of Japan and the knights of western Europe were similar because they all were influential during periods of? Who founded radium?