resurrect anti-black sentiment. Emancipation Proclamation Slavery for the Confederacy's 3.5 million blacks effectively ended in each area when Union armies arrived; they were nearly all freed by the Emancipation Proclamation. The last Confederate slaves were freed on June 19, 1865, celebrated as the modern holiday of Juneteenth. Slaves in the border states and those located in some former Confederate territory occupied before the Emancipation Proclamation were freed by state action or (on December 6, 1865) by the Thirteenth Amendment. The Emancipation Proclamation enabled African Americans, both free blacks and escaped slaves, to join the Union Army. About 190,000 volunteered, further enhancing the numerical advantage the Union armies enjoyed over the Confederates, who did not dare emulate the equivalent manpower source for fear of fundamentally undermining the legitimacy of slavery. During the Civil War, sentiment concerning slaves, enslavement and emancipation in the United States was divided. Lincoln's fears of making slavery a war issue were based on a harsh reality: abolition did not enjoy wide support in the west, the territories, and the border states. In 1861, Lincoln worried that premature attempts at emancipation would mean the loss of the border states, and that "to lose Kentucky is nearly the same as to lose the whole game." Copperheads and some War Democrats opposed emancipation, although the latter eventually accepted it as part of the total war needed to save the Union. At first, Lincoln reversed attempts at emancipation by Secretary of War Simon Cameron and Generals John C. Frémont (in Missouri) and David Hunter (in South Carolina, Georgia and Florida) to keep the loyalty of the border states and the War Democrats. Lincoln warned the border states that a more radical type of emancipation would happen if his plan of gradual compensated emancipation and voluntary colonization was rejected. But compensated emancipation occurred only in the District of Columbia, where Congress had the power to enact it. When Lincoln told his cabinet about his proposed emancipation proclamation, which would apply to the states still in rebellion on January 1, 1863, Seward advised Lincoln to wait for a victory before issuing it, as to do otherwise would seem like "our last shriek on the retreat". Lincoln laid the groundwork for public support in an open letter published in response to Horace Greeley's "The Prayer of Twenty Millions". He also laid the groundwork at a meeting at the White House with five African American