Copeland was already known before the Harpers Ferry raid for rescuing a runaway enslaved man from his captives in 1850. In 1859, he joined Brown’s men, recruited by his uncle, fellow raider Lewis Leary. His task was to help take over Hall’s Rifle Works along the Shenandoah River. When trying to escape, Copeland was captured in the river. He was found guilty of murder and trying to start a slave rebellion, and was hanged on December 16, 1859. Before his execution, he said, "I could not die for a better cause. I had rather die than be a slave."