Easy defeat of foreign invaders is obviously positive, so it couldn’t be a factor that would topple an empire. Security is good.
In the period 1865 to 1910, the immigrants faced many challenges and also embarked in the opportunities available to them in the North and the West. The main challenge was related to job hunting. I hope my answer has come to your help. God bless and have a nice day ahead!
Some think it was called this because of how the skin turned dark at the late stages of the disease, but it was more likely called "Black" to reflect the dark and horrible time in history.
Both have Executive and Legislative branches in their government and both have the power to veto.