Southern states felt threatened by ____________, who worked to end slavery.
To find the answer to this question, we can look into the historical context of the Southern states during the time when slavery was being challenged.
In the given sentence, it mentions that "Southern states felt threatened by ___________." The missing term appears to refer to a person or a group of people who were working to end slavery. One well-known historical figure who advocated for the abolition of slavery was Frederick Douglass, but there were many other activists, politicians, and organizations involved in this movement as well.
To provide a more specific answer, we need to consider the time period. If we look at the era leading up to the American Civil War, one prominent figure who threatened the Southern states by their efforts to end slavery was Abraham Lincoln. As a political leader, Lincoln opposed the expansion of slavery into new territories and later issued the Emancipation Proclamation, which declared slaves in Confederate-held territories to be free.
In summary, Southern states felt threatened by individuals like Abraham Lincoln and other abolitionists who worked to end slavery.