After the Emancipation Proclamation authorized freed slaves to "be received into the armed service of the United States", former slaves who escaped from plantations or were liberated by the Union Army were recruited into the United States Colored Troops regiments of the Union Army, as were black men who had not been slaves. The US Colored Troops made up 10 percent of the Union death toll—15 percent of Union deaths from disease and less than 3 percent of those killed in battle. Losses among African Americans were high. In the last year and a half and from all reported casualties, approximately 20 percent of all African Americans enrolled in the military died during the war. Their mortality rate was significantly higher than white soldiers. While 15 percent of US Volunteers and just 9 percent of white Regular Army troops died, 21 percent of US Colored Troops died.