The Treaty of Versailles caused long-term instability in Europe (and parts of Asia) by ignoring the nations who had lost WWI. The treaty didn't provide any support for the nations who had lost, creating resentment in the hearts' of their people. This disunity allowed for the rise of facist dictators post-WWI, eventually causing World War II.
The legislative branch must approve any Presidental appointments unless a veto is used.
Periodization is a useful concept to apply when studying history. Periodization is defined as "the process or study of categorizing the past into discrete, quantified named blocks of time in order to make the study and analysis of history easier to facilitate." This is often challenging however, because it is hard to determine the beginning and the end of a period.
