One hundred fifty years ago this spring, Congress passed what some call the most important modification to the U.S. Constitution ever. The 14th Amendment fixed problems left over from the Civil War, a task that proved to be surprisingly difficult. The amendment’s ambivalent legacy has rendered it a vital piece of our constitution, with ongoing relevance to today’s contentious policy debates.

The 14th Amendment solved two critical problems. First, it addressed the status of newly freed slaves, declaring them citizens by virtue of their birth on American soil. Second, the amendment protected the rights of citizenship when states violated them. After slavery ended in 1865, the states of the former Confederacy began targeting African Americans with prejudicial laws designed to keep them economically and civically inferior. “Black codes” passed by state governments restricted the freed peoples’ economic options and criminalized their impoverishment, making them an exploited labor class that was “free” only in name. The federal government stepped in.

Many considered this revolutionary. Up to then, constitutional theory held that liberty was safest when protected by the states, far away from the kind of powerful central government the American colonies had rebelled against. But Reconstruction demonstrated that the states themselves could also undermine liberty. By compelling the federal government to act against state discrimination, the 14th Amendment made it the ultimate guarantor of citizens’ rights.

Those rights were specified in the amendment itself, which stated that all citizens were entitled to equal protection and due process of the law. The privileges and immunities that went with citizenship were specified in the Civil Rights Act, a momentous piece of legislation Congress also passed in 1866. These included the right to access the legal system, as well basic rights of personal security. Finally, the framers of the amendment viewed it as encompassing the liberties set forth in the Bill of Rights.

While the 14th Amendment and Civil Rights Act worked together to give meaning and security to American citizenship, both faced uphill political battles getting passed. Of course, southern conservatives opposed efforts to protect the rights of freed slaves, but since Congress had refused to seat representatives from former Confederate states, they had little say.

The real trouble came from the Republicans who had proposed the amendment in the first place. Critics complained that it fundamentally re-crafted the relations between the federal government, which existed only to represent the interests of the states internationally, and the state governments, which regulated affairs between individuals and government. Robert Hale of New York declared the amendment “an utter departure from every principle ever dreamed of by the men who framed our Constitution,” amounting to “a grant of the fullest and most ample power to Congress” to pass laws as states did. Others worried that the amendment’s champions were “introducing a power never before intended to be conferred upon Congress,” or that “it takes away from these States the right to determine for themselves what their institutions shall be.”

The amendment’s defenders countered that federal power would be triggered only when states violated the rights naturally due all free people. All the states needed to do to avoid it was to cease discriminating.

“If the States would all observe the rights of our citizens, there would be no need of this bill,” declared Massachusetts Senator Henry Wilson. “The practice of the States leaves us no avenue of escape, and we must do our duty by supplying the protection which the States deny.”

While proponents won the day, it was not an easy fight. Maine’s own senator during Reconstruction, William Pitt Fessenden, illustrated the era’s ambivalence over federal power. Fessenden supported the 14th Amendment, and even the vote for African Americans, declaring to the southern states that “until you ratify an amendment to the Federal Constitution providing for equal civil and political rights … you must remain unrepresented in Congress.” But when southern states balked at accepting it, he advised that Congress “had better leave the matter where it was” rather than compel their submission.

When the recalcitrant President Andrew Johnson vetoed the amendment, Fessenden refused to side with the radical wing of his party, and voted against Johnson’s impeachment. He found the whole crisis trying; “treachery on the one hand and folly on the other have almost disheartened me,” he lamented.

In the short term, proponents of the amendment won the day. But older views of federal power persisted beyond Reconstruction, severely limiting the amendment’s ability to guarantee the rights it was designed to secure. Justices raised on the antebellum logic of states’ rights federalism circumscribed the amendment in the post-war years, limiting its applicability to instances of state rather than private discrimination, and of violations of civil rather than political rights.

Armed with this narrow view, the Supreme Court ultimately decided in the case of Plessy v. Ferguson (1896) that Jim Crow laws segregating the races did not violate the 14th Amendment’s guarantees of equal protection — a clear departure from the framers’ original intent.

Thankfully, much has changed over the last 120 years. But debates over the meaning and purpose of the 14th Amendment continue to animate important discussions in public policy — about how far the benefits of American citizenship should extend, and about the nature of those benefits. Some wish to repeal the principle of birthright citizenship while others have sought to extend 14th Amendment protection to questions of marriage equality.

Clearly, our view of federal power has changed. Americans now encounter the federal government every day: in the form of the paper money we spend, the regulations that keep us safe, the taxes we pay, and the representatives we elect. Whether we favor or oppose this ubiquity, history reminds us that this was not always so.

Only one thing is sure. As its framers intended, the 14th Amendment will continue to shape the ways we think about liberty in a dynamic and ever-changing country. As one of its framers declared in 1866, the 14th Amendment sought nothing more than “the care of the Republic, not only for the present, but for all the hereafter.”

Patrick Rael is professor of history at Bowdoin College and a project scholar for the Maine Humanities Council. Throughout 2016, the Maine Humanities Council will offer ways for Mainers to talk with one another about equality and inclusiveness, in commemoration of the 150th anniversary of the passage through Congress of the 14th Amendment. Visit for more information.