The US Congress denied President Adams the ability to send troops into South America to continue the campaigns against Spanish holdouts from the American-Spanish War.
As such President Adams, not used to being denied in Congress, justified their position by saying that "Americans are no longer welcome in South America after this fracture, for wherever we step, we step on their feet."
During the State of the Union address in 1828 President Adams wrote that "Americans must no longer act as the mediators of peace, nor the constables of the world. For if we do such a thing we will only damage ourselves and kill good men in wars that are not ours, and above all that we, as Americans, should stay in America and out of world affairs."
The effects of this were as far reaching as they were correct. America could not function as world constables without draining the economy and the people. Americans, after this drew into themselves and began to become nearly "oblivious" to world problems and only focused on their own, going to war only when it involved them.