After the fall of Fort Sumter in April 1861, both sides scrambled to create armies. President Abraham Lincoln issued a call for 75,000 volunteers to suppress the rebellion. This immediately caused the secession of four additional states, including Virginia. The United States Army had only around 16,000 men, with more than half spread out in the West. The army was commanded by the elderly Lt. Gen. Winfield Scott, veteran of the War of 1812 and the Mexican-American War. On the Confederate side, only a handful of federal officers and men resigned and joined the Confederacy. The formation of the Confederate States Army was a matter initially undertaken by the individual states.