What was the League of Nations, and what was its significance?
As World War I drew to a close, United States President Woodrow Wilson began to worry about the lasting consequences of the unhealthy political climate that he believed had led the world to war, and he designed a plan for Fourteen Points of peace that represented his vision for a safer world. Unfortunately, when the leaders of the victorious Allied Powers met in 1919 for the Paris Peace Conference, they were not interested in the kind of "just peace" that Wilson had in mind. They demanded that Germany take the blame for the war, and pay reparations for the damage and loss that had been incurred due to their involvement. Wilson's suggestion for the creation of a League of Nations was agreed upon, with the participating member states pledging to work together to sustain a lasting peace throughout the world. However, when Wilson returned to the United States, both the League of Nations and the Treaty of Versailles that he asked the US government to approve were met by it with intense opposition and disapproval, and the United States failed to join the League of Nations or to ratify the Treaty.
Why did the United States enter World War I?
Although they had previously refrained from entering the war due to the policy of neutrality that the United States had practiced since the enactment of the Monroe Doctrine in 1823, Germany's decision to resume waging unrestricted submarine warfare made it impossible to continue doing so. This German policy, which culminated with the sinking of the Lusitania, a British ocean liner carrying a number of American passengers, combined with German intelligence discovered by the United States that suggested Germany might form an alliance with Mexico, changed the course of the war.
Is the comma placement in the sentence below correct? The quarterback, with the help of his team, managed to lead them to victory in the last game.
Yes, that would be the correct usage of commas for that sentence. You are using a parenthetical phrase, and you indicate a parenthetical phrase with a comma on each side of it when it is featured in the middle of the sentence.