In the short term, the voyages led to the destruction of the natives of the lands that Columbus found. Some of them were killed outright. Others were enslaved. Many died of diseases brought by the Europeans.
French and Indian war (also known as the seven years war), led tensions between the 13 colonies and Britian. This is because in this war france lost New France to the British. When taxes began to rise in the colonies and Americans were starting to rebel, French were happy to help since it would be a sort of revenge since losing their colony in North America.
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!
I'm guessing you are talking about the Eastern Roman Empire, or the Byzantine Empire.
the Byzantine Empire a) remained strong for several centuries, until it fail to the Ottoman Turks at ~1346 ad
hope this helps