Answer:
The threats that both the European nations and the Native tribes implied for the United States in military terms were one of the triggers, among others, for the government of the United States to decide to modify the fundamental norm that governed the destinies of the nation, the Articles of Confederation.
Thus, until the passage of the Constitution of the United States in 1787, the federal government did not have the possibility of rapidly constituting an army, but it depended to a great extent on the collaboration of the states. For this reason, the nation as such was unable to defend itself effectively against external threats.
With the sanction of the Constitution, the federal government was granted the possibility of constituting a unified national army, in addition to granting the President of the nation the title of commander-in-chief of said armed forces.