Above the Missouri Compromise Line.
Secondary Sources<span>: The primary </span>sources<span> can be of great help to the historian if he has acquire thorough knowledge of the background through the </span>study<span> of </span>secondary sources, i.e. the works of the great and important<span> historians of the proposed area and period of research.
I got this answer from historydisscusion.net</span>
Joseph Stalin wanted to regain Russia's (USSR) land that was lost in the previous World War I, (The Great War) basically wanted to take over the world, little by little. To do this, he eliminated anyone who he thought would be more powerful than him, such as the important rulers in the Central Planning Committee.
World war 2 officially started in 1939
