Final answer:
The image portrays Peter, an escaped enslaved man in 1863, whose scarred back evidences the brutal treatment slaves endured and helped fuel abolitionist efforts during the American Civil War.
Step-by-step explanation:
The historical event depicted in the image of Peter showing his scarred back is related to the atrocities of slavery during the American Civil War period. This photograph was taken during a medical examination in Baton Rouge, Louisiana, in 1863, and it represents the severe physical abuse that Peter, an escaped enslaved man, suffered under the hands of an overseer.
The image became a powerful symbol for the abolitionist movement, as it visually documented the cruel treatment that enslaved individuals faced in the United States. It served to bolster the message of the northern abolitionists against the inhumanity of the institution of slavery. Peter, the man in the photograph, managed to escape to Union Army lines, became a soldier, and fought against the violent system that had inflicted such damage upon him and many others.