When the case came before the high court Adams, who was nearly deaf, was in rare form. Arguments took place in the Old Supreme Court. His actual argument lasted 8½ hours, over two separate days. One of the justices hearing the case had died, so a short delay took place between the start and the end of the argument.
As he argued in the old room of the Supreme Court, Adams pointed to the framed Declaration of Independence. With emotion he asked:
" Is it possible to speak of this demand
[to send the Africans back to Cuba]
in language of decency and moderation?
...Has the expunging process of black
lines passed upon these two Declarations
of Independence in their gilded frames?
Has the 4th of July '76 become a day of
ignominy and reproach?"
Because he was trying to win his clients' freedom, and because no other case precisely on point had been argued before (or since) in the Supreme Court of the United States, Adams had little "legal" precedent. What he did have, though, counted the most. What he argued was the eternal law of nature that every person is free. And it was that law - the eternal law - to which Adams staked his claim.
"...I know of no other law that reaches
the case of my clients, but the law of
Nature and of Nature's God on which
our fathers placed our own national
existence."
Associate Justice Joseph Story told his wife (in a letter) that Adams' argument was "...extraordinary...for its power, for its bitter sarcasm, and its dealing with topics far beyond the records and points of discussion." In short, Adams had done an awesome job.
It took about one month for the Supreme Court to render its decision. Justice Story wrote the majority opinion. There was one dissent.