US History: Chapter 5, Exercise 3 — Possible Solution
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CONFIRMED
The Pennsylvania Abolition Society (1775); that Garrison and Douglass agitated
for abolition; that John Brown used armed force.

NOT CONFIRMED
The Underground Railroad's operation, the American Anti-Slavery Society's
founding date, Uncle Tom's Cabin's role, the split between immediate and
gradual abolitionists, and Harriet Tubman.

WHAT WOULD BE NEEDED
A fuller source on abolitionism specifically, read in full rather than as a
partial summary, ideally cross-checked against a second source.