Here are the answers to the questions based on the historical context provided:
Question 1: Violations of treaties with the Sioux
Question 2: the discovery of gold in Colorado
Question 3: by discouraging students from practicing their tribal beliefs
Question 4: He used the military to protect African Americans from violence.
Question 5: the ratification of the Fifteenth Amendment in 1870
Question 6: His veto of the Civil Rights Act of 1866
Question 7: to protect the civil rights of African Americans
Question 8: to ensure that African Americans would have a voice in the government
Question 9: the Dred Scott decision
Question 10: The shortage of food and weapons in the Confederacy
Question 11: the return to power of white Democrats
Question 12: It undermined the civil rights that African Americans had gained during Reconstruction.
Question 13: the loss of states' rights to control their own laws
Question 14: his veto of the Reconstruction Acts
Question 15: President Andrew Johnson
Question 16: It kept African Americans from exercising their rights.
Question 17: African American voters were disenfranchised.
Question 18: The Reconstruction Amendments are essential to reuniting the country and rebuilding the South.
Question 19: It was allowed as long as the facilities provided to both races were equal.
Question 20: It changed the social landscape of the nation.
Question 21: Sharecropper must plant more crops next year to help earn enough to pay off the debt.
Question 22: Emancipated slaves left the South to escape racial discrimination and to seek economic opportunities in the North and West.
These answers reflect the events and conditions surrounding the Civil War and Reconstruction, as well as the subsequent social and economic changes in America.