On 15th April, 1861, Abraham Lincoln called on the governors of the Northern states to provide 75,000 militia to serve for three months to put down the insurrection. Some states responded well to Lincoln's call for volunteers. The governor of Pennsylvania offered 25 regiments, whereas Ohio provided 22. Most men were encouraged to enlist by bounties offered by state governments. This money attracted the poor and the unemployed. Many black Americans also attempted to join the army. However, the War Department quickly announced that it had "no intention to call into service of the Government any coloured soldiers." Instead, black volunteers were given jobs as camp attendants, waiters and cooks.
On 30th August, 1861, Major General John C. Fremont, commander of the Union Army in St. Louis, proclaimed that all slaves owned by Confederates in Missouri were free. Abraham Lincoln was furious when he heard the news as he feared that this action would force slave-owners in border states to help the Confederates. Lincoln asked Fremont to modify his order and free only slaves owned by Missourians actively working for the South. When Fremont refused, he was sacked and replaced by General Henry Halleck.
In May, 1862, General David Hunter began enlisting black soldiers in the occupied districts of South Carolina. He was ordered to disband the 1st South Carolina (African Descent) but eventually got approval from Congress for his action. Hunter also issued a statement that all slaves owned by Confederates in the area were free. Abraham Lincoln quickly ordered Hunter to retract his proclamation as he still feared that this action would force slave-owners in border states to join the Confederates. However, unlike the case of Major General John C. Fremont in Missouri the previous year, Lincoln did not relieve him of his duties.
In January 1863 it was clear that state governors in the north could not raise enough troops for the Union Army. On 3rd March, the federal government passed the Enrollment Act. This was the first example of conscription or compulsory military service in United States history. The decision to allow men to avoid the draft by paying $300 to hire a substitute, resulted in the accusation that this was a rich man's war and a poor man's fight.
Abraham Lincoln was also now ready to give his approval to the formation of black regiments. He had objected in May, 1862, when General David Hunter began enlisting black soldiers into the 1st South Carolina (African Descent) regiment. However, nothing was said when Hunter created two more black regiments in 1863 and soon afterwards Lincoln began encouraging governors and generals to enlist freed slaves.
John Andrew, the governor of Massachusetts, and a passionate opponent of slavery, began recruiting black soldiers and established the 5th Massachusetts (Colored) Cavalry Regiment and the 54th Massachusetts (Colored) and the 55th Massachusetts (Colored) Infantry Regiments. In all, six regiments of US Colored Cavalry, eleven regiments and four companies of US Colored Heavy Artillery, ten batteries of the US Colored Light Artillery, and 100 regiments and sixteen companies of US Colored Infantry were raised during the war. By the end of the conflict nearly 190,000 black soldiers and sailors had served in the Union forces.