The Wisconsin Supreme Court could not successfully apply the 10th Amendment to this case, because the powers it claimed are delegated to the federal government in the Constitution: Article III vests judicial power in the US Supreme Court and inferior courts created by Congress; it expressly construes this judicial power to include all cases in law and equity arising under the Constitution and the Laws of the United States; and it grants appellate jurisdiction on matters of "law and fact" to the US Supreme Court. Article IV also affirms that "This Constitution, and the Laws of the United States which shall be made in Pursuance thereof … shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby" If each state court had the power to overrule federal law in its own jurisdiction, then there would be no force behind federal government at all, and that was clearly not the intent of the Constitution.

The Fugitive Slave Law under which Booth was convicted was a federal law made in pursuance of Article IV, Section 2 of the Constitution, which (regrettably) stated: "No Person held to Service or Labour in one State, under the Laws thereof, escaping into another, shall, in Consequence of any Law or Regulation therein, be discharged from such Service or Labour, but shall be delivered up on Claim of the Party to whom such Service or Labour may be due." The Wisconsin Supreme Court offered several reasons for why it viewed the Fugitive Slave Law of 1850 to violate parts of the US Constitution, but even if the Wisconsin court was right, it lacked jurisdiction over the matter. Only a federal court could rule on the case.

As much as I absolutely admire the Wisconsin Supreme Court for standing up to slavery and unjust legislation, and as crucially important as I think it is to invoke the 10th Amendment against an overreaching federal government, it remains nonetheless wrong to distort history to give the 10th Amendment greater prominence than it really had or to purport that there was some kind of coherent 10th Amendment movement in early Wisconsin.

The Wisconsin abolitionists who founded the Republican Party in 1854 tried to use the 10th Amendment when it suited them (e.g. against the Fugitive Slave Law) — but they loathed it when it worked against their aims, as in the Dred Scott case mentioned by this article. The Wisconsin Republicans hated the Supreme Court's decision in Dred Scott, which cited the 10th Amendment to rule that the federal government had no authority to outlaw slavery in new states or territories — a ruling that struck at the very core of the original Republican platform, which was, ahem, to prohibit slavery in new states and territories!

Ultimately, the 10th Amendment to the Constitution is just one sentence in a very long and complex document which must be read in its entirety to be properly understood and applied, and which must sometimes be changed — as it was over the issue of slavery — to promote greater social justice.