<span>Many diseases need a large population in order to survive. Hunter Gatherer populations do not offer this. Diseases will often strike, kill a few people and then disappear until the population comes into contact with an outsider again. In contrast, civilized society offers a large enough population so that a disease is able to constantly stay alive and be spread. Therefore, disease does not spread faster in agrarian societies, it just spreads more unchecked.</span>
Answer:
Lacking food and ravaged by smallpox disease earlier introduced by one of the Spaniards, the Aztecs, now led by Cuauhtemoc, finally collapsed after 93 days of resistance on the fateful day of 13th of August, 1521 CE. Tenochtitlan was sacked and its monuments destroyed
Explanation:
A difficulty that had to be overcome during the building of the Transcontinental railroad was Native raiding on work camps.