Nowadays, 193 nations are members of the United Nations.
These states are sovereign and they have equal representation in the UN General Assembly. Since it was created in 1945 up to the present, many nations have been incorporated; some of the original members are France, the UK, The USA, Argentina, Canada, Brazil, etc
The reason why it takes a long time to ratify the Articles of Confederation is that U.S. just declared independent from Britain, in other words, they just passed the Declaration of Independence, and in order to keep a country on track, they need some sorts of form of government, and they don't want to repeating the history, or have another tyrant, or a king, to rule over them again, which is a part of reason why they declared independent (the actual reasons is the king taxes us for no reason and we can't participate in the government), so they need all of the 13 states to approve, or sign, the Articles of Confederation, majority of them signed it, some of them having issues about the rights in the Articles of Confederation, so someone, I forgot his name, promised to includes all of the rights into the Articles of Confederation, which they can't do it instantly, which later known as the Bill of Rights (the first 10 amendments), so it takes longer to get the whole Articles of Confederation to be approved, or ratified.
Hope this help, my English is not that well so please excuse for it.
Answer:
The reasons of the rise of nativism in the 1920s and 19030s were the increase of immigrants, the call of the citizens arguing the loss of access to opportunities and the bigger difficulties they suffered due to the competitive environment.
