The impact of the Battle of Antietam on public sentiment in the North was Increased support for the war.

Following the battle, which was the bloodiest single day in American history, many Northerners felt a renewed commitment to the Union cause, bolstered by the tactical advantage gained over Confederate forces. The battle also provided President Lincoln with the opportunity to issue the Emancipation Proclamation, which framed the war as a fight against slavery, further galvanizing support among abolitionists and the general public. Overall, the battle fostered a sense of determination and resilience in the Northern states.