How Slavery Radicalized Lysander Spooner

'How does a radical libertarian abolitionist attorney from the North go from passionately defending the United States Constitution–arguing that the document prohibited slavery from its ratification–to declaring the United States Constitution “unfit to exist” two decades later?

Lysander Spooner wrote The Unconstitutionality of Slavery in 1845 as a response to William Lloyd Garrison, who opposed the Constitution due to its apparent preservation of slavery.'

https://mises.org/power-market/how-slavery-radicalized-lysander-spooner