Shields Green was known as the “Emperor.” He was a fugitive slave who was executed in 1859 for his role in John Brown’s Raid on Harper’s Ferry.
Green was born a slave in South Carolina around 1925 to 1936. As a young man he escaped through the Underground Railroad network to Rochester, New York, where Frederick Douglass provided shelter and introduced him to radical abolitionists.

In 1959, Green traveled along with Douglass to Chambersburg, Pennsylvania where he encountered a meeting with John Brown, the white abolitionist from Ohio. It was Brown’s hope to enlist Douglass to support in coordinating an armed uprising among slaves through a raid on the federal arsenal in Harper’s Ferry, Virginia. During the meeting, Green listened to both Brown’s and Douglass’ side and ultimately accompanied Brown.

Green left the meeting with Brown’s son Owen and joined other black men who had allied with Brown, including Lewis Leary and John Anthony Copeland, both residents of Oberlin, Ohio. The raid failed, and Green was charged with treason, murder and leading slaves to rebel. Using the 1857 Dred Scott Decision that ruled against citizenship for slaves, Green’s attorney successfully argued that as an escaped slave who lacked citizenship, Green could not be charged with treason. However Green was found guilty on the two other counts and sentenced to death. He was hanged alongside Copeland on December 16, 1859.

Green’s body was never recovered for a proper burial, instead his body went to Winchester Medical School in Virginia, where students were allowed to dissect his body.

source:
http://newsone.com/2813488/shields-green-john-copeland-hanged-1859/
https://en.wikipedia.org/wiki/Shields_Green