April 6-7: Battle of Shiloh (also known as the Battle of Pittsburg Landing), a major Union victory that resulted in the capture of Corinth, Mississippi, and the opening of the Mississippi River to Union control.
April 25: Capture of New Orleans, Louisiana, by Union forces, giving the Union control of the mouth of the Mississippi River and a strategic advantage in the war.
May 1: Union forces under General George McClellan began the Peninsula Campaign, an attempt to capture Richmond, Virginia, the Confederate capital.
May 31 - June 1: Battle of Seven Pines (also known as the Battle of Fair Oaks), a Confederate victory that halted McClellan's advance on Richmond.
June 1: President Abraham Lincoln issued the Emancipation Proclamation, which declared all slaves in the Confederate states to be free.
June 25-July 1: Seven Days Battles, a series of Confederate victories that forced McClellan to retreat from his position near Richmond.
August 29-30: Second Battle of Bull Run (also known as the Second Battle of Manassas), a Confederate victory that boosted morale and gave the Confederacy hope of winning the war.
September 1: Robert E. Lee became the commander of the Confederate Army of Northern Virginia.
September 17: Battle of Antietam (also known as the Battle of Sharpsburg), a bloody and indecisive battle that resulted in a Union tactical victory but failed to achieve its goal of destroying Lee's army.
October 3: Battle of Corinth, a Union victory that secured control of the Mississippi Central Railroad and further weakened Confederate defenses in the West.
November 7: President Lincoln issued the Preliminary Emancipation Proclamation, which stated that all slaves in Confederate-held territory would be free on January 1, 1863.
December 11-15: Battle of Fredericksburg, a Confederate victory that resulted in heavy Union casualties and marked the end of the year's major military campaigns.