As an American, I owe a tremendous debt of gratitude to many, many people who have risked and given their lives to defend our liberty. But as I reflect on the recent Supreme Court decision in McDonald v. City of Chicago, I thought I should take a moment to mention four Americans who have made a relatively uncelebrated contribution to the freedom I cherish and enjoy. I owe a special debt to four black men, and one gun.

The most important of these men, to me, was my father. When I was a boy, he and my mother moved our family of six from the Terrace Village public housing projects in Pittsburgh’s Hill District to a predominantly white neighborhood. While many of our neighbors welcomed us, we were not welcomed by all. I recall a brick through the front window, and other incidents. But burned into my memory is the Sunday evening when my father was beaten with a tire iron on the street in front of our home, and in front of us, his four little children. Those three young white men were never caught.

When my father, with his surgically reconstructed eye socket and jaw, was released from the hospital, he did something he never once considered when we lived in the projects. He bought a gun.

Every evening after that, before going to bed, I and my siblings would go out onto the front porch to say goodnight to my father as he sat in his chair, shotgun across his lap, with its black barrel glistening under the porch light. I never once felt unsafe. I never once had trouble sleeping. My sense of security did not come from the Pittsburgh Police, or from the law. My sense of security came from my father, and his gun.

There were no more incidents, at least not any that I can recall, after my father exercised his Second Amendment right. It was his contribution to “non-violence” in our neighborhood.

Just like the millions of children of our nation’s police officers, we were instructed to never touch my father’s gun. And like those millions of children, we did not touch it. My father believed that it was his first responsibility to protect his family, and that it was reasonable for him to avail himself of a firearm to do so. But so many black men before him have been denied this basic right, and it is important to thank the other black men who have made important contributions in preserving it.

Foremost among these, in my mind, is Frederick Douglass. The self-educated runaway slave turned abolitionist newspaper editor and orator, Douglass was alarmed at the unaddressed violence unleashed on black people in the wake of the Civil War. As Douglass pointed out in his autobiography, black Americans could not count on the government to protect them; they had to defend themselves against the rash of lynchings committed by the Ku Klux Klan and even state and local authorities. Citizenship, according to Douglass, rested upon three boxes: “the ballot box, the jury box, and the cartridge box.”

As Tim Sandefur of the Pacific Legal Foundation recently pointed out, Douglass was wise to realize that black Americans needed to rely on themselves for their own safety and security. Douglass argued that the post-Civil War Amendments, the Thirteenth, Fourteenth, and Fifteenth, were written to protect the freed slaves from a backlash by the Southern states. The 14th Amendment’s Privileges or Immunities Clause says that: “No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States.” Douglass urged the federal government to enforce the Constitution as written, to secure for black Americans, indeed for all Americans, the “privileges or immunities” of full citizenship.

Douglass’s plea fell on deaf ears. In 1873, the Fourteenth Amendment’s “privileges or immunities” clause was gutted in The Slaughterhouse Cases, where the Supreme Court upheld the State of Louisiana’s decision to close down butchers competing with a politically-well-connected private monopoly. The Court ruled that this clause only protected rights of national scope, such as the right to access foreign embassies or the right to protection while traveling the high seas. This was, as Georgetown Law Professor Randy Barnett recently noted, “a preposterous interpretation — these were hardly the rights congressional Republicans in the aftermath of the Civil War were most concerned to protect in the wake of the terrible abuses of free blacks and white unionists by Southern states.”

Nevertheless, the “privileges or immunities” clause was dead. Moribund, as the constitutional law scholars like to put it. It has been dead for one hundred and thirty two years.

But the “privileges or immunities” clause is still there in the Fourteenth Amendment to the Constitution, still in the actual document. A handful of scholars have kept up the fight to get these words noticed again. These scholars are not ones you will have heard of, especially if you have a law degree from a top law school. Most of these scholars toil away in think tanks, since the doors of many law schools have been shut to them. In fact, if you have attended a top law school, your first reaction is likely to have been, “don’t you mean ‘privileges and immunities’ clause?” While you may have been exposed to the “privileges and immunities” clause of Article IV, your con law professor is unlikely to have mentioned the “privileges or immunities” clause of the 14th Amendment.

This reaction is understandable, because constitutional law scholarship in most law schools has become a closed, insular conversation among both liberal and conservative law professors who have, in their own ways, become completely at ease with the sweeping scope of government power in a world devoid of the “privileges or immunities” clause. Liberals dislike the “privileges or immunities” clause for fear that it might legitimate the kinds of unenumerated rights they hold in contempt, like the rights to property and freedom of contract. It is not a coincidence that these are precisely the rights that the Reconstruction Congress sought to protect with the Civil Rights Act of 1866. Likewise, conservatives, including the plurality in McDonald, are uncomfortable with the “privileges or immunities” clause because it legitimates unenumerated rights, like the right to privacy recognized in Griswold v. Connecticut and Roe v. Wade. Justice Alito demonstrated his discomfort with economic liberty too, when he asked in oral argument whether the “privileges or immunities” clause included the right to contract, clearly hoping that the answer was “no.”

The top constitutional law scholars were completely caught off guard when a third black man, Justice Clarence Thomas, reinvigorated the “privileges or immunities” of citizenship in McDonald v. City of Chicago two weeks ago. In McDonald, the court struck down a Chicago ordinance banning handguns. Justice Thomas had been reading the scholarship on the “privileges or immunities” clause over the last several decades. He read it and understood it. And while this scholarship did not matter in the opinion of many of our nation’s top constitutional law professors, it did matter in an opinion that, itself, matters a lot.

In his concurrence to the four other justices in the 5-4 majority, Justice Thomas refused to stretch the 14th amendment’s “due process” clause to guard the right to bear arms. Instead, he bravely read the constitution the way it was written, with little regard for how his opinion would be attacked from both the left and the right. His opinion acknowledged that the right to bear arms was clearly one contemplated by the framers of the “privileges or immunities” clause. Justice Thomas stood with Fredrick Douglass, and stood up for a black man trying to protect himself and his family in a city where the police admittedly cannot.

Otis McDonald is that black man, the fourth to whom I owe so much. As I attempt to raise my two sons to be strong, confident and secure Christian men, I am grateful that this 76-year-old grandfather fought for my right to protect them from those who might try to do them harm.

I purchased a gun several years ago, when I became concerned for the safety of my young family after receiving a verbal racial assault in our 21st century Northern California neighborhood. Perhaps I am the only Stanford Law professor who owns guns, including the one that once graced my father’s lap on that porch forty years ago. As an American, I am grateful for that gun. I am also grateful for the four black men who have made it possible for my sons to sleep at night, secure in the knowledge that I, and it, will do what is necessary to protect them.