<span><span><span>The crust: low density silicate rock, 5-70 km thick. There are two distinct types of crust.<span><span>Continental crust is variable in thickness and composition. Thickness ranges from 5-70 km. The composition ranges from mafic to felsic.</span><span>Oceanic crust is uniform in thickness and composition. It is 5-6 km thick and is mafic in composition.</span><span>The differences in thickness and density between continental and oceanic are responsible for the existence of ocean basins due to isostatic balance as the crust floats on the more dense mantle.</span></span></span><span>The mantle: high density, ultramafic silicate rock which can flow when subjected to long duration stresses. The mantle is over 2900 km thick and makes up over 80% of the volume of the Earth. The mantle is not molten!</span></span><span>The core: iron and nickel, liquid outer region with a solid center. The core is just over half the diameter of the Earth.</span></span>
Answer:
The period known as the reconstruction started after the civil war. Abraham Lincoln planned for the reconstruction of the South during the war since the Union occupied a big area there. He did not want the nation to be in turmoil for long and wanted to unite it and get it on its feet as quickly as possible.
The 16th amendment in 1913 permits Congress to lay and collect taxes on incomes, from whatever source derived, without apportioning it among the states or basing it on the US Census. Ratification was completed on February 3, 1913. Before that customs duties and excise taxes were the primary sources of federal revenue. Answer: The ratification of the 16th amendment.
Answer:
"In the late 1800s, people in many parts of the world decided to leave their homes and immigrate to the United States. Fleeing crop failure, land and job shortages, rising taxes, and famine, many came to the U. S. because it was perceived as the land of economic opportunity. Others came seeking personal freedom or relief from political and religious persecution, and nearly 12 million immigrants arrived in the United States between 1870 and 1900. During the 1870s and 1880s, the vast majority of these people were from Germany, Ireland, and England - the principal sources of immigration before the Civil War. Even so, a relatively large group of Chinese immigrated to the United States between the start of the California gold rush in 1849 and 1882, when federal law stopped their immigration."
https://www.loc.gov/classroom-materials/united-states-history-primary-source-timeline/rise-of-industrial-america-1876-1900/immigration-to-united-states-1851-1900/
