Why did the way of life of many indigenous people in the plains region of north america end in the late 1870s

How did the new working class of the industrial revolution differ from the working classes of the earlier, farm based economy?

Take another look at the population pyramid for france in 1950. notice the disparity between the male and female populations in the 55 to 70 year-old age group. what historical event could account for this disparity?

The three estates social system in france ensured balanced representation of all people and treated each social group fairly. true or false ? why?