"Getting them freed" was not at all a goal of the war. It eventually was adopted as a goal about 18 months after the war started, but the intent of sending Armies into the south was not to free the black people, it was to control the economic powerhouse that was the Southern trade with Europe.
People nowadays do not know this, but the South produced 75-85 % of all the European trade, and because the Federal government was paid through tariffs, the South was effectively paying for 75-85% of all the cost of running the Federal Government.
An independent South would have wrecked the Northeastern shipping and finance industries, and the powerful men of New York were not going to have that.
The North went to war to stop the South from damaging the economics of the powerful people of New York and Washington DC.
In other words, the same people who are "the establishment" today.
But very much contrary to your point, the North was not afraid of any "Economic Powerhouse" (that term in relation to a Southern economy based on agriculture and slave labor is laughable). No, it was the South that was deathly afraid the high tariffs which protected Northern industry from European imports would lead to increased retaliatory tariffs on their goods, leaving cotton and tobacco income damaged in the crossfire. That was the economic impetus to secession and war. If slavery had anything to do with it, the Southern States' fear of the growing populations and political power in the North leading to their realization that they would never have the power to keep it in place by extending it west into new States and Territories, was the link.
Lincoln was very clear before and after his election that he (and most Northerners were of the same mind) had no intention of interfering with the "Peculiar Institution" where it already existed. But secession happened anyway, followed by attacks on Federal installations left within the new Confederacy, and even a far from secret plan to assassinate a President Elect on his way to his inauguration as he passed through Baltimore.
Secession was the first "cause" of the war, followed by a North incensed by attacks on Federal troops and unexpected humiliating defeats on the battlefield. As the casualty lists published in the papers in Northern towns and villages grew so did anger and a deep desire for revenge. It was only when "Preserving the Union" lost its luster in a bath of bloodshed that a new justification, a noble cause (and what's more noble to the American mind than "Freedom"?) turned the Northern cause into an anti-slavery crusade. And by that time overwhelming Northern numbers and industrial might, coupled with British queasiness over slavery and caution about creating a dangerous enemy in a re-United States, and Lincoln's reelection in 1864 made the end result inevitable, a very different country than the one preceding the war, stronger, more united, and destined to become the most powerful military, economic, and political force in history.