The story begins in New Salem, Illinois, where a young and ambitious Abraham is working as a store clerk. Determined to make something of himself, he reads voraciously and becomes involved in local politics. His skills as an orator and his burgeoning sense of justice earn him respect in the community, and eventually, he wins an election to the Illinois State Legislature. Despite his outward success, Abraham faces personal struggles, including the death of his beloved Ann Rutledge. This event deeply affects him, yet he perseveres, believing that he can achieve his dreams and make a difference.

As Abraham’s political career advances, he navigates personal relationships that shape his future. He marries Mary Todd, whose ambition matches his own and who envisions great things for her husband. Yet, their relationship is tested by differing personalities and public pressures. Meanwhile, Abraham's moral convictions lead him to address the pressing issue of slavery. His debates with rival Stephen Douglas highlight his evolving beliefs and growing leadership potential. The film portrays his rise from humble beginnings to a pivotal moment in American history but concludes before depicting his most significant political achievements and national impact. The journey focuses on his internal and external battles, setting the stage for his eventual legacy.