When presidential candidate Bernie Sanders spoke to a crowd of 7,000 at a rally in Birmingham, Alabama last Monday, the national celebration of Martin Luther King, Jr. Day provided the most immediate and obvious context for the senator’s campaign visit. While Senator Sanders undoubtedly benefited from the excitement around the celebration of Dr. King’s legacy, the history of southern progressivism goes even further back in time than the 1960s, back to a time of economic and social unease that, in many ways, mirrors our own historical moment.

Of course, Sanders rightly honored the memory of Dr. King and the mid-century civil rights struggle during his brief stay in Birmingham. The presidential hopeful took time to tour the 16th Street Baptist Church where the Ku Klux Klan murdered four African American girls in 1963, and Cornell West and Ohio state senator Nina Turner laced their rousing introductory speeches with references to Dr. King.

Like Dr. King, Sanders spoke about the connections between racism, income inequality, and the nation’s interventionist foreign policy. In drawing attention to the symmetry between King’s platform and his own, Sanders aligned his campaign with the civil rights movement’s most radical and most forgotten agendas. Undoubtedly the most progressive candidate for president, Senator Sanders called on this radical legacy as he staked a claim for his campaign within the Republican-dominated Deep South.

Yet the legacy of progressive politics in the South goes much deeper than the 1960s. In fact, Sanders did not need to tour the 16th Street Baptist Church to prove his link to progressive politics. He could have tapped into the history of Boutwell Auditorium, the very building where his crowd congregated.

On November 20, 1938, the Southern Conference for Human Welfare (SCHW) gathered an interracial crowd of about 1,200 southern liberals, radical labor leaders, and progressive politicians in the building then known as the Municipal Auditorium. Others in attendance included first lady Eleanor Roosevelt, Supreme Court Justice Hugo Black, New Dealers Clifford and Virginia Durr, Mary McLeod Bethune of the National Association of Colored Women, and Alabama governor Bibb Graves. Led by the Birmingham-native Joseph Gelders and Lucy Randolph Mason, a labor organizer from Virginia, the SCHW responded to the abysmal findings in the Roosevelt administration’s Report on the Economic Conditions of the South, which famously described the region as the nation’s “number one economic problem.”

At the time, the South, like much of the nation, was reeling from the effects of the Great Depression and stood in dire need of solutions for low wages, electoral inequalities, segregation, and educational reform. The combination of this radical platform and interracial crowd drew the attention of Birmingham’s then-unknown police commissioner Theophilus Eugene “Bull” Connor. After Connor told the crowd they could not “segregate together,” the conference attendees split by race with whites on one side of the auditorium, blacks on the other. Mrs. Roosevelt sat deliberately between the two sections after being required by police to move out of the black section.

Ultimately, the SCHW could do little to address the problems that catalyzed their movement. A lack of funding and charges of Communism evaporated much of their political capital, and the coalition disbanded in 1948. But the issues raised by the SCHW–-economic injustice, racial inequality, and dire educational rankings–-still plague the South with a tenacity that defies logic. The Solid South politics of the Democratic Party that hamstrung progressive reform in the twentieth century does so again under the Solid South of the Republican Party in the twenty-first, even if the name has changed.

Last Monday, Senator Sanders announced to the crowd that “There must be some kind of mistake. I was told Alabama was a conservative state,” a comment that met with cheers from the thousands gathered in Boutwell Auditorium. Sanders will have to weather the same issues of financial shortfalls and redbaiting that undercut the SCHW and the civil rights movement to sustain a movement in the South. But Sanders possesses something that those movements did not, namely the cultural shifts created by those prior generations of activists. If he can keep returning to the South, bringing with him his message of racial and economic equality that resonates so well with Bible Belt liberals, then Sanders might just go from preaching to the choir to making some conversions.

Perhaps some of the Sanders faithful knew the historical significance of the building. Or perhaps they knew it as the space in which the segregationist Dixiecrat Party nominated Strom Thurmond for president in 1948, stealing the Deep South’s electoral votes from Harry Truman. Or perhaps they simply knew the building as a place to catch a concert.

Whether or not the crowd thought about the history of the building where they congregated, Sanders should not be surprised when his platform touches base with voters in Alabama or anywhere else in the South. The political message of racial and economic justice has taken root in the region before, from the SCHW to Dr. King, and Sanders drew at least twice as many supporters as Donald Trump’s Birmingham rally back in November.

While time will tell if our current moment will produce the next chapter in that history, one thing is clear. Regardless of the South’s reputation for white supremacy and political conservatism, progressive precedents can be found throughout its history–sometimes right where we are standing.