Why the American Presidency Exists
To put it bluntly, the reason why the framers committed to the position of the presidency is that it was the only option to ensure their vision for the United States came to fruition. The revolutionary war and the relationship between the colonies and Britain are examples the framers would utilize when figuring out what they wanted for the new country. For the idea behind the United States to succeed, the threats that came from a hereditary monarchy or a deeply centralized government could not exist. The civil liberties and American values that were at the forefront of the establishment of our country needed to take a different approach from what was common for states at the time and that is what would lead to the American presidency.
While I get into the specific reasons behind the formation of the American presidency, it is important to note that the position would come through a sort of trial and error. As the United States was initially evolving both during the revolutionary war and after, the framers realized what was needed to ensure their vision for the American government came to be. Drawing from ancient Rome and Greece, it was known that the United States needed to be a republic. The first attempt at an established government would be through the articles of confederation, but that would not be sufficient. The articles of confederation would allow for a Confederation Congress, but the powers granted to them would be too little and create issues. Without a doubt, the biggest issue that arose would be the ability to act in foreign affairs, as the Confederation Congress had little power to enact in this realm of politics.
It was known to the framers that they would have to adapt the American government from their previous experience for a few reasons besides what is listed above. Firstly, without a unified head of power, the United States had trouble being viewed as legitimate in international politics, which greatly weakened the country. Second, the issue of national security arose due to the lack of a unified head of the national government that prevented a coordinated national defense. The last reason I will list is the ability to enforce laws is next to impossible without a head of state. These reasons listed above are the most pressing issues that arose during the tenure of the articles of confederation and I would argue that this experimentation was necessary to lead to an American presidency. By the time these issues were identified, it was determined that the best way to address the concerns of national security, the ability to enforce national law, and foreign affairs, would be through the position of president of the United States that had just enough power to achieve the vision of America without risking tyranny.