Abraham Lincoln's main objective for the Union during his presidency, particularly during the Civil War, was to preserve the United States as a unified nation. He believed that the Union was essential for maintaining democracy and ensuring the survival of the republic. While issues such as slavery were deeply intertwined with the conflict, Lincoln's primary goal was to prevent the secession of the Southern states and to restore the Union.
Overall, he viewed the preservation of the Union as critical not only for the United States but also for the broader ideals of freedom and democracy that the nation represented. As the war progressed, the issue of emancipation became increasingly central to his vision, culminating in the Emancipation Proclamation in 1863, which aimed to weaken the Confederate war effort and ultimately led to the abolition of slavery. However, the overarching goal remained the restoration and preservation of the Union.