How did the united states assert itself as an independent nation?

One reason could be that in 1823 the United States developed a policy that they will not be tolerating any interference or colonialism by Europe anymore which was called “The Monroe Doctrine” because of the President James Monroe who first stated the doctrine. Though the term “Monroe Doctrine” was coined much later in 1850.

i dont no the claim so it's hard to answer but i think he would go to the people to decide. : ) ; )

is this a true or false question? ?