From Fugitive Slaves to Sanctuary Cities

At the height of recent immigration enforcement efforts in Minnesota, Florida Governor Ron DeSantis compared sanctuary policies and the refusal of some state and local officials to cooperate with federal authorities—actions he characterized as obstructing federal law—to the way some Northern states resisted enforcement of the Fugitive Slave Acts from the late 18th through the mid-19th century. He didn't draw a moral equivalence between slavery and illegal immigration; he framed the issue as one of the rule of law and federal supremacy under Article VI, Clause 2 of the U.S. Constitution.

Interestingly, similar historical references have surfaced on the other side of the debate—but with a very different emphasis.

U.S. Representatives Alexandria Ocasio-Cortez and Ayanna Pressley have suggested that there are moments in history when laws become so unjust that defiance is warranted, applying that logic to current immigration enforcement debates.

Gavin Newsom has been more explicit, pointing to the Fugitive Slave Act era as an example of states refusing to participate in enforcing federal laws they viewed as unjust, and describing that resistance as part of a broader American moral tradition.

When public officials invoke comparisons that touch even indirectly on slavery, people understandably become wary, and reflexively resistant to the comparison. That’s one reason many politicians speak in generalities on the subject. They gesture toward history but leave it to others to sort through the implications. They know that explaining historical nuance is difficult work, and it rarely survives opportunistic political debate.

So what, exactly, are these elected officials referring to?

When the Framers negotiated the United States Constitution, they struck a series of difficult compromises—none more consequential than those that accommodated slavery. Among them was the Fugitive Slave Clause (Article IV, Section 2, Clause 3), which required that a person “held to Service or Labour” who escaped into another state be returned. But the provision stipulated no clear mechanism to enforce it.

Five years later, Congress addressed that gap with the Fugitive Slave Act of 1793, which authorized slaveholders to seize alleged fugitives in free states and bring them before a judge or magistrate for return, while penalizing those who aided their escape.

What had been a regional institution was now tied to a national obligation—one that many in the North were unwilling to accept.

In response, several Northern states enacted “personal liberty laws” designed to impede enforcement. These laws guaranteed jury trials for alleged fugitives, required strict proof of ownership by slaveholders, provided habeas corpus protections to challenge unlawful detention, penalized kidnappers who seized free Black residents, and in some cases prohibited state officials from participating in captures.

That friction came to a head in 1842 when Maryland slavecatcher Edward Prigg forcibly removed Margaret Morgan from Pennsylvania without following state legal procedures. Pennsylvania prosecuted him, and the case reached the Supreme Court, which ruled that federal authority over fugitive slave enforcement was supreme and that state laws interfering with it were unconstitutional. But the Court also held that states were not required to use their own officials to enforce federal law.

That created a paradox: it affirmed federal authority while limiting its ability to make it effective in practice.

In response, Northern states shifted from regulating enforcement to avoiding it. New personal liberty laws prohibited state participation altogether, forcing the federal government to rely increasingly on its own resources. This frustrated Southern states and contributed to the passage of the far more stringent Fugitive Slave Act of 1850, enacted as part of the Compromise of 1850.

The 1850 law expanded federal enforcement mechanisms, denied alleged fugitives a jury trial, and penalized those who helped fugitives, including officials who failed to enforce the law. It also created federal commissioners to handle cases, bypassing local courts. It was a significant victory for the South, but it sparked even more intense resentment and resistance in the North.

That resistance took many forms. Northern juries often refused to convict those accused of aiding fugitives. Enforcement attempts also sparked mass resistance. In 1851, abolitionists stormed a courtroom in Boston and freed fugitive slave Shadrach Minkins from federal custody, helping him escape to Canada. In response, the federal government began using more troops and marshals to safeguard proceedings.

That same year, a crowd in Syracuse broke into a jail and freed Missouri fugitive slave William “Jerry” Henry. Then, in 1854, a similar attempt to rescue Anthony Burns failed, and federal authorities responded with overwhelming force, deploying troops to ensure his return to slavery.

As resistance grew, enforcement became more coercive, more visible, and more politically costly. Federal law could still be carried out, but it happened at the expense of deepening the division between North and South. Northerners increasingly viewed enforcement as morally intolerable; Southerners saw resistance as a breakdown of law and order.

The system that had once depended on compromise and cooperation was beginning to fail, leaving fewer and fewer paths to resolve the conflict without war.

It’s important to draw a distinction that often gets blurred in modern debate. The right to oppose the law—to protest it, criticize it, and work to change it—is firmly protected. But that isn’t the same as a legal right to ignore or obstruct it. In our system, civil disobedience has always occupied a different space: not as a protected entitlement, but as a deliberate choice to accept legal risk in the name of a higher principle. States, for their part, may decline to use their own resources to enforce federal law, but they can’t nullify it or interfere directly with its execution. The line between opposition and obstruction has always mattered.

Today, while the stakes and circumstances are very different from the fugitive slave issue, some of the language and tactics ring familiar. The resistance to fugitive slave laws carried a profound moral urgency rooted in the injustice of slavery, an institution that stands apart in its severity and consequence. Modern immigration enforcement operates in an entirely different legal and moral context.

The question, then, is not whether the two are equivalent—they aren’t—but whether the methods of resistance and level of obstruction we see today are proportionate to the injustices they claim to address, and whether they bear meaningful resemblance to those used against the morally indefensible laws of the past.