The primary factors for migration among southern African Americans were segregation, an increase in the spread of racist ideology, widespread lynching (nearly 3,500 African Americans were lynched between 1882 and 1968), and lack of social and economic opportunities in the South.
Cultural exchange and the change in global population are the immediate consequences of the columbian exchange. Proliferation of invasive species and some communicable diseases are the most important byproducts of the columbian exchange.
The origin of the 1905 revolution goes back to the recently-concluded Russo-Japanese War, in which Japan placed a serious check on Russia's power to expand in East Asia. Many Russians saw this outcome as a source of humiliation, and supported an effort to remove the Tsar because of it.
