February 1 – Texas secedes from the Union, the sixth State to do so.
February 6 – Under combined land/river forces led by Ulysses S. Grant and Andrew H. Foote, Federal forces capture Confederate-controlled Fort Henry on the Tennessee River.
February 16 – a second major blow is delivered in the Western theater in the same month when General Grant demands the ‘unconditional surrender’ of the Confederate forces at Fort Donelson on the Cumberland River in Tennessee. C.S.A. General Simon B. Buckner surrenders the fort to Grant.
February 22 – Jefferson Davis, from Kentucky, is formally inaugurated as President of the Confederate States of America, having served as provisional President.
February 25 – Nashville, Tennessee, becomes the first southern State capital to be captured by the Union, without a shot even being fired. It will remain in Federal control the remainder of the war. Also on this day, Lincoln signs the Legal Tender Act creating the first national currency.
February 25 – National Currency Act goes into effect for the United States, (later to become known as the National Banking Act of 1864) making it easier to finance the war with government bonds.
February 17, 1864 – H.L. Hunley – Confederate submarine – sinks a Union ship then disappears in the Charleston Bay. The entire crew is lost.
February 27 – first Federal prisoners are delivered to Andersonville Prison in Sumter County, Georgia. Some 43,000 Union soldiers will eventually spend time at the prison. Over 13,000 men died there. Less than 350 escaped.
February 1 – Sherman begins Carolinas Campaign.
February 3 – February 3 – Lincoln meets with Confederate Peace Commission at Hampton Roads, Virginia.
February 6 – Robert E. Lee is named commander in chief of all Confederate armies by Confederate Congress.
February 17 – Columbia, South Carolina, falls to Sherman.
February 18 – Charleston seized by Union troops.
February 22 – Joseph E. Johnston re-called to command forces against Sherman.
For a complete timeline of the American Civil War see the Civil War Gazette’s timeline here.