Cohens lived in DC, which had a lottery.He tried to sell tickets in Virginia
and got arrested, since lotteries were illegal in Virginia.Since DC was ruled by Congress, the DC
lottery had the weight of Federal Law.Virginia convicted Cohens and appealed to the US Supreme Court.The Supreme Court affirmed the
decision, but only on the grounds that the DC lottery was not authorized in
Virginia.Virginia had argued
that, under the 11th Amendment their decisions were
unreviewable.Supreme Court
disagreed, and basically affirmed the Martin v. Hunter's Lessee decision.