All though only in his first term, Elliot Fremont spent the two years following the Second War of Secession as a lame-duck President. Having been the one who had not only failed to keep the nation together, but the one who pushed the southern states to go their own way made his administration a laughing stock in their own country.
During the Congressional elections immediately following the war, every single Progressive Party seat in either house was lost to the Federalists. For the first time in almost a hundred years Congress was controlled by one party.
A year and a half later a recently retired general who's family was a Federalist institution, Adam Kennedy, threw his hat in the ring for the Federalist Party's presidential nomination. Kennedy,one of the generals during the war not to completely embarrass himself, he had actually halted several Confederate strikes into Columbia, won the nomination after winning not the only the Iowa, but the New Hampshire primary as well.
The Progressive Party, desperate to simply survive the upcoming election, refused to renominate their sitting-president candidate, a first in American history. Instead they nominated Chicago mayor Christopher Day, who did all he could to draw attention away from the Progressives' botching of the war and toward social issues, where the Progressives traditionally polled better then the Federalists.
The damage was done though. Kennedy carried every state remaining in the DS save for Day's home state of Illinois, which he barely won at that.
With that the Progressive Party fell into history's dustbin, leaving a power vacuum on the American political system's left wing. It would be Eugene Attlee's Socialist Party that would rise to give the disaffected hope.
The newly inaugurated President Kennedy stated that the country could not simply go guns blazing into the south, that for now the DS had to accept the existence of the Confederate States as a reality, but promised "vindication" against those who had wronged the Democratic States.
Under Kennedy American confidence rebounded. In contrast to the situation in the Confederacy, the economy was on the rise, and the Federalist administration had begun it's purging and rebuilding of an armed forces that had previously shown to be incompetent.
Perhaps the biggest change, at least in the public's eye, was the situation of the capital. Washington lay within the state of Columbia, itself bordering Confederate Virginia to the south. Fearful of the capital's vulnerability in the event of a new war with the CSD, the new Federalist Congress passed The Capital Act, temperaraly moving the capital of the DSA from Washington to Boston "until such time as this relocation is no longer imperative to the safety of the government of the Democratic States of America."
While urging the American public to be patient in wanting revenge against the southern Confederacy, Kennedy had promised vindication. The DSA was beyond angry at the world for its loss of half its territory, and in the collective minds of the American people, someone had to be punished.
If the DSA was going to let the Confederacy be for the time being then looking south wasn't the answer. Instead the newly rejuvenated nation looked north to an old adversary.