Why might have anti slavery advocated of 1861 invoked Joel Barlow to decry the evils of slavery?

Anti-slavery advocates in 1861 may have invoked Joel Barlow to denounce the evils of slavery because he was an early American poet and diplomat who expressed criticism of slavery in his works, emphasizing the immorality and inhumanity of the institution. By referencing his writings, these advocates could draw on his powerful rhetoric to underscore their own arguments against slavery.