It's Black History Month. So it's time to talk about Frederick Douglass, Harriet Tubman, the Rev. Dr. Martin Luther King Jr . . . and also Tom Watson.

Watson was a leader in the People's Party, which called on blacks and whites to unite against rich bankers and landowners. "You are made to hate each other because upon that hatred is rested the keystone of the arch of financial despotism which enslaves you both," Watson declared in 1892. "You are deceived and blinded that you may not see how this race antagonism perpetuates a monetary system which beggars both."

Thomas Watson
Wikimedia Commons
Thomas Watson

But Tom Watson was white, not black. So he isn't the kind of person we tend to discuss during Black History Month, which focuses almost exclusively on the lives of African Americans.

That's a mistake. Of course we should use this month to emphasize black contributions and achievements, which are too often ignored or downplayed in our schools and colleges. But we must not neglect key white allies like Watson, who remind us that black and white struggles for justice have always been intimately linked.

And that's a message I'd like every American — but especially every white American — to hear this February, at a hugely polarized moment in our national history.

As a host of surveys have confirmed, white supporters of Donald Trump often view racial minorities and immigrants as a threat to their interests. Concentrated in areas of low economic growth and mobility, Trump voters say minorities and newcomers are using government assistance to elbow out whites in the battle for prosperity and security.

There's not a lot of empirical evidence for those claims, which reflect the isolation of the pro-Trump communities as much as anything else: When you don't know many people who look different from you, it's much easier to blame them for your woes. But it won't do to dismiss Trump supporters as ignorant bigots, which will simply make them dig in their heels. And they're unlikely to be moved by a litany of black heroes and heroines recited dutifully by teachers each February.

Instead, we should use Black History Month to remind white people that their foreparents often fought alongside blacks, and for the very same things. Fueled by our nasty political culture, many whites imagine that blacks are their perpetual competitors and antagonists. But our history suggests otherwise.

Consider Bacon's Rebellion, the first big poor people's revolt, in colonial Virginia. It was led by Nathaniel Bacon, a white indentured servant. But it also drew African American slaves, who joined hands with impoverished whites in a quest for property and dignity. One of the last bands to surrender in the rebellion included 80 blacks and 20 whites.

During the Civil War, black soldiers joined the Union Army in droves to defeat the Confederacy. In the Progressive Era, W.E.B. DuBois united with white activists to create the NAACP. White lawyers defended the Scottsboro Boys, the nine African Americans who were falsely accused of sexual assault in the 1930s. And black and white workers came together to organize the Congress of Industrial Organizations, which raised wages for cash-strapped Americans during the Great Depression.

Finally, the civil rights movement of the 1950s and 1960s enlisted Americans of every color and class. As everyone learns during Black History Month, now-Rep. John Lewis was beaten during the Freedom Rides. But so were white allies like Tom Hayden, who was jailed in Georgia — Lewis' home state — for trying to desegregate a railway station.

None of this takes anything away from African Americans, who had the most at stake — and at risk — in the struggle for freedom. Nor does it deny the racism, hostility, and violence that they encountered at every step of the way.

And some of it came from former allies, like Tom Watson. After several failed campaigns for office under the People's Party ticket — including an ill-fated run for president in 1904 — Watson would devolve into one of the most vicious racists in American political history. He was a key figure in winning the disenfranchisement of Southern blacks, whose votes he had so eagerly solicited a few years earlier. And he was an open advocate for lynching, which he deemed the only defense against rapacious African American men.

"What does Civilization owe to the Negro?" Watson asked, in a typically hateful 1905 editorial. "Nothing. Nothing!! NOTHING!!!"

Actually, our entire country owes a huge amount to African Americans. They built our houses and roads; they farmed our land; they fought our wars. Most of all, though, they extended and redefined human freedom. It's too bad that we need a special month to remember that.

But we must not forget that they united with white people, too, at many different junctures. The alliances were often fraught, and sometimes they failed. But that's all the more reason that we need to recall them, especially during Black History Month. Especially now.

Jonathan Zimmerman teaches education and history at the University of Pennsylvania. He is the author (with Emily Robertson) of "The Case for Contention: Teaching Controversial Issues in American Schools."