<span>the invasion of Japan that cost tens of thousands of American lives. </span>
The Inca culture was one of the most developed in pre-Columbian America. Among their achievements, was their architectural ability. Inca structures were made of stone that fit together, with extraordinary stability. The buildings have survived for centuries, with no use of mortar, in areas that are prone to earthquakes and volcanic activity.
The Inca also developed calendars based on astronomical observations. Astronomers understood equinoxes, solstices and zenith passages. Numerical information, particularly for administration, was stored in <em>quipu</em> strings.
In terms of art, Inca ceramics were highly advanced, although most of their silver and gold work was melted down by the Spaniards.
They were also advanced in medicine, performing skull surgeries successfully and with high survival rates.
The consequences of the Black Death were numerous and varied. Countless workers died, ravaging families through failed means of survival and causing personal affliction; landowners who used laborers as tenant farmers were also impacted. It is estimated to have abolished 30 percent to 60 percent of the European population.
The American revolution opened so many different trade opportunities that the colonist night longer needed Britain and their manufacturers
The reason why some of the founders of the American republic considered the lack of a national executive and judiciary under the Articles of Confederation as one <span>of the documents great strenghts is because the favored a weak central government and "strong" individual states--since they were afraid that a strong central government would become tyrannical. </span>
