Final answer:
One of President Lincoln's major challenges at the start of the Civil War was convincing the border states to voluntarily end slavery.
Step-by-step explanation:
One of President Lincoln's major challenges at the start of the Civil War was convincing the border states to voluntarily end slavery. While Lincoln detested slavery, his primary goal at the beginning of the war was to preserve the union rather than abolish slavery. He also feared that pushing for immediate abolition would threaten the loyalty of slaveholding border states and alienate white volunteers who might refuse to serve alongside black men. However, as the war progressed and the number of escaped slaves seeking refuge behind Union army lines grew, Lincoln and Congress found it increasingly difficult to avoid the issue of slavery.