I would go with the first one, abolitionist because it means some one who wishes to abolish. And the whole Civil war was focused on Abolishing slavery.
abolitionist ;
The domain-specific term that would likely be used in an informative research essay on Civil War photography is "A. abolitionist," as it relates to the movement to end slavery. This term is important because it connects the visual documentation of the Civil War to broader social issues, including the fight against slavery. Photography during this era played a significant role in influencing public perceptions and advancing the abolitionist cause.
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