that escaped or liberated slaves belonging to anyone who participated in or supported the rebellion "shall be deemed captives of war, and shall be forever free of their servitude, and not again held as slaves." Later on, Lincoln's Emancipation Proclamation was an executive order of the U.S. government issued on 1 January 1863, changing the legal status of 3 million slaves in the Confederacy from "slave" to "forever free". Slaves were legally freed by the Proclamation and became actually free by escaping to federal lines, or by advances of federal troops. Many served the federal army as teamsters, cooks, laundresses, and labourers, as well as scouts, spies, and guides. Confederate General Robert Lee once said "The chief source of information to the enemy is through our negroes." Plantation owners sometimes moved the Blacks they claimed to own as far as possible out of reach of the Union army. By "Juneteenth" (19 June 1865, in Texas), the Union Army controlled all of the Confederacy and liberated all its slaves. The owners were never compensated; nor were freed slaves compensated by former owners. The border states were exempt from the Emancipation Proclamation, but they too (except Delaware) began their own emancipation programmes. When the Union Army entered Confederate areas, thousands of slaves escaped to freedom behind Union Army lines, and in 1863 many men started serving as the United States Colored Troops. As the war dragged on, both the federal government and Union states continued to take measures against slavery. In June 1864, the Fugitive Slave Act of 1850, which required free states to aid in returning escaped slaves to slave states, was repealed. The state of Maryland abolished slavery on 13 October 1864. Missouri abolished slavery on 11 January 1865. West Virginia, which had been admitted to the Union in 1863 as a slave state, but on the condition of gradual emancipation, fully abolished slavery on 3 February 1865. The 13th Amendment to the U.S. Constitution took effect in December 1865, seven months after the end of the war, and finally ended slavery throughout the United States. It also abolished slavery among the Indian tribes, including the Alaska tribes that became part of the U.S. in 1867. Notable abolitionists White and Black opponents of slavery, who played a considerable role in the movement. This list includes some escaped slaves, who were traditionally called abolitionists. John Quincy Adams Jeremy Bentham John Brown