Drawn and engraved by William Russell Birch, 1755-1834, on Wikimedia Commons

What the Founders Didn’t Know—But Their Children Did—About the Constitution

Alison L. LaCroix—

Conflicts between the federal government and the states dominate our current moment in American law and politics. From controversies over who governs at the southern border, to the regulation of abortion, to voting rights, firearms, healthcare, and immigration, the issues at the center of public debate today center on the fraught relationships between multiple levels of government. 

Yet these are not new debates. Arguments about federalism—the relationship between the federal government and the states—raise questions about the nature of the Union that date back to the nation’s founding. The Constitution not only failed to resolve these questions; it created them. As a result, it was left to the generation of Americans who came after the founding era to confront the unsettled nature of American federalism and to forge novel approaches to the specific problems caused by that lack of settlement.

In order to understand the federalism debates of our own moment, we must bring back into the spotlight an era that has tended to be absent from constitutional history: the period between the founding and the Civil War. My new book The Interbellum Constitution: Union, Commerce, and Slavery in the Age of Federalisms focuses on the decades between 1815 and 1861. The book argues that this period—flanked by two wars, the War of 1812 and the Civil War—was the origin point of much of modern American constitutionalism, especially with respect to the relationships among levels of government.

The interbellum period laid out the federalism landscape that we know today. This landscape was formed by constitutional structure, doctrine, practice, and text. It was also shaped by debate—in courtrooms, in Congress, and in the public square. One of the central arguments in my book is that constitutional law itself was changing in this period. There was, in short, an “Interbellum Constitution.” And the principal intellectual and doctrinal terrain on which it took shape was that of commerce—the idea of “commerce” as an activity in which people engaged, and the Commerce Clause of the Constitution as a technical framework for understanding how that activity was to be regulated and encouraged.

Ever since the early nineteenth century, the commerce power has been one of the main arenas in which the Supreme Court confronts the complexities of the relationship between the federal government and the states. Today, on issues ranging from healthcare (the Affordable Care Act, or “Obamacare”), to medical marijuana, to gun regulation, to crime, Congress uses its power to regulate commerce to reach a vast range of activities. And the Court follows suit, interpreting the scope of the commerce power to determine the constitutionality of Congress’s regulations. The interbellum period shows us why and how this happened.

From the dawn of the nineteenth century, Americans linked the idea of commerce with the imperatives of nationhood: trade, foreign affairs, and war. As suggested by the title of this image from 1800 of a Philadelphia shipyard bustling with work on one of the new nation’s new frigates, preparation for war went hand in hand with the defense of commerce.1

During the interbellum period, despite the many controversies that split Americans, there was one point on which nearly everyone agreed: the United States was a commercial Union. Even southern slaveholders agreed with this proposition; indeed, their livelihoods depended on it. But what exactly did a “commercial Union” entail? Who governed it? Here was where few people could agree.

The standard account of American constitutional history is incomplete because it overlooks the significance of commerce—trade, money, and, in a broader sense, exchange—to the struggles that defined the period between the founding and the Civil War. A widely shared imperative to create a commercial Union elevated arguments about ferryboats, hogsheads of liquor, and bales of textiles into questions of constitutional significance. Everyday commerce created the conflicts, and the language of the Constitution gave citizens, lawyers, and judges the rhetorical tools to escalate those arguments. 

Commerce was everywhere in the early-19th-century United States. As the English author and reformer Harriet Martineau observed in 1837, following extensive travels in America,

“[I]t is very comprehensible to the traveller why this new country so far transcends others
of the same age in markets and means of transport. The ports of the United States are,
singularly enough, scattered round the whole of their boundaries. Besides those on the
seaboard, there are many in the interior; on the northern lakes, and on thousands of miles
of deep rivers. No nook in this country is at a despairing distance from a market.”2

Note two key elements of Martineau’s description: she connected “markets” and “means of transport,” and the transportation she has in mind is water borne. Ports dotted the era’s maps of the United States, from the northern lakes to the thousands of miles of deep rivers (culminating, of course, with the Mississippi). The country was connected by waterways running between trans-shipment points and markets, including the recently built Erie Canal, completed in 1825.

And something else was at work in Martineau’s observation as well. “No nook in this country is at a despairing distance from a market,” she wrote. Commerce had an emotional component as well. The sentiments of the people of an increasingly far-flung union could be harmonized through trade and commerce.

One year after Martineau wrote, a young Illinois politician named Abraham Lincoln struck a similar note in 1838. Lincoln told his listeners at the Young Men’s Lyceum in Springfield, Illinois, that American government was based upon “the attachment of the People.” Attachment was a sentiment, an emotion in modern terms. The government was imperiled when the “best citizens” suffered an “alienation of their affections from the Government.” Lincoln’s solution was for “law”—in particular, the Declaration of Independence and the Constitution—to become the “political religion” of the nation.3

As Lincoln’s note of caution suggested, there was reason to worry about the health of the nation’s political religion in the years after 1815. Alongside the optimistic promises of commerce came concerns about how that commerce was to be governed—and by whom. Where would the power over commerce lie—with which level of government? The states, or what 19th-century Americans referred to as the “general government”—that is, the federal government?

Interbellum Americans had to engage in constitutional creativity because the Constitution simply did not provide clear answers. The founders’ vision of federalism consisted in a set of agreements about structure. They agreed to divide authority between the federal government and the states. Where the line of division fell depended on what the subject was.

But not all the subjects set forth by the Constitution were neatly apportioned between the states and the federal government. The Constitution also sketched a substantial middle zone of powers. In this middle zone, competing governments operated. Their powers overlapped. Both Congress and the states could claim the authority to regulate a given activity. In the interbellum period, as ports sprang up, the river trade flourished, and the Union and its markets expanded, this zone of concurrent power also grew. The concurrent powers of the Constitution became more important than ever because they governed some of the most significant areas of the nation’s activity. These powers included the power to regulate commerce, to regulate migration, and to tax.

Each of these powers also implicated the growing constitutional crisis over slavery, in particular its expansion into new states and territories. Like commerce, slavery raised difficult questions of boundaries: between federal and state power, and also between states. Different states might have different regimes with respect to slavery. Maryland protected slaveowners’ asserted right to own other human beings, while Pennsylvania passed a series of anti-kidnapping laws intended to protect fugitives and free persons of color. Questions about the extraterritorial effect of supposedly local laws quickly melded issues of slavery and interstate commerce.

Why does this tale of early-19th-century commerce matter? For three reasons:

First, in order to have a complete understanding of U.S. constitutional law, we must not to lose sight of the constitutional creativity of these decades, with the founding on one hand, and the Civil War and Reconstruction on the other. During this half-century, the central public debates in America centered on issues that raised profound federalism questions: commerce, migration, and slavery, among others.

Second, the period reminds us that the meaning of the Constitution was not settled or fixed in 1787. Important and unsettled questions were being debated for the next decades (and indeed, today). The best way to gain purchase on meanings, plural, is to attend to these debates.
To understand what the Constitution meant at a given time, one must listen to producers of constitutional discourse—a broader group than the usual small cadre of statesmen and justices.

Finally, the period is important because it helps give context to our own moment of intense political and legal debate. Many commentators cite the Civil War as an analogy to—and a cautionary tale for—the current moment. But a more accurate comparison might not be the war itself, but rather the five decades of slow-boiling constitutional conflict that preceded it. The similarities between those years and today provide context, insight, and perhaps a warning, to us all.


  1. Birch, William Russell, Engraver. Preparation for War to defend Commerce. The Swedish Church Southwark with the building of the Frigate Philadelphia. Pennsylvania United States Philadelphia, 1800. Photograph. https://www.loc.gov/item/2002718892/. ↩︎
  2. Harriet Martineau, Society in America, 2d ed. (London: Saunders & Otley, 1837), 2:171-72. ↩︎
  3. Abraham Lincoln, “The Perpetuation of Our Political Institutions” (1838), in The Political Thought of Abraham Lincoln, ed. Richard N. Current (Indianapolis: Bobbs-Merrill, 1967), 15-17. ↩︎

Alison L. LaCroix is Robert Newton Reid Professor of Law and an Associate Member of the Department of History at the University of Chicago. The recipient of a National Endowment for the Humanities Fellowship, she is a scholar of U.S. legal history specializing in constitutional law, federalism, and eighteenth- and nineteenth-century legal thought. In 2021, President Biden appointed her to the Presidential Commission on the Supreme Court of the United States.


Recent Posts

All Blogs

Categories