The belief that slavery was fading let Washington avoid opposing it.

Evidence

In 1785, he led a delegation of abolitionists to Mount Vernon to convince the future first president of the United States to join their movement. But George Washington declined to sign the petition or publicly support the Methodists’ anti-slavery efforts, on the premise that “it would be dangerous to make a frontal attack on a prejudice which is beginning to decrease.” Washington—perhaps knowingly and strategically—exonerated himself from taking a political stand against slavery on the grounds that progress was being made. Slavery persisted, and grew, protected by the argument that it was going away. — Nikole Hannah-Jones et al., The 1619 Project, 1253

Categorization

• QUESTION: Contested empirical claim vs reframing thesis: is Washington’s stated ‘progress’ justification genuine belief or strategic exoneration? This is exactly the sort of historian dispute worth pinning down.
• SEED: The ‘inevitable decline’ fallacy as a rhetorical technique — historical actors and institutions justifying inaction on the claim that change is already underway.