Suffragists hold banners in front of the White House in 1917. One banner reads: “Mr. President How Long Must Women Wait For Liberty.” (Library of Congress)

Elizabeth Cobbs, a history professor at Texas A&M and a senior fellow at Stanford’s Hoover Institution, is the author of “ The Hello Girls.”

One hundred years ago, on June 4, 1919, Congress approved by joint resolution a constitutional amendment giving women the right to vote, sending the amendment to the states for ratification. After seven decades of campaigning, the women’s suffrage movement was on the cusp of realizing its goal.

The reason for the long delay, especially in the drawn-out final months of the effort, lay less in sexism than in racism.

By 1919, women had mostly beaten down the arguments that their voting would imperil female fertility, men’s masculinity or the nation’s vitality. Instead, feminists had to contend with claims that, by granting black women the right to vote, suffrage would ultimately risk restarting the Civil War.

Anyone who thinks the United States has made little progress on racial issues over the past century should read the Congressional Record of 1918 and 1919. Those annals, particularly of the Senate debate, shed light on the climate in which reformers labored to improve the rights of all women, and on the sordid compromises sometimes involved in progress.

Southern Democrats were the staunchest foes of the 19th Amendment. Even after President Woodrow Wilson, a Democrat, reversed his opposition in 1918, he was unable to persuade his own party to use its congressional majority to give women the vote.

The 19th Amendment would give black women the same rights granted to black men after the Civil War with the 15th Amendment, which South Carolina Sen. Ellison Smith denounced on the Senate floor — without a single Northern hand raised in objection — for having “jeopardized the civilization that you and I represent.”

Sen. Thomas Hardwick of Georgia counseled Northern legislators to “pause before you put your feet into the very footprints of the same mistake that your fathers made just after the Civil War.”

It had taken every bit of racist ingenuity to erect the Jim Crow barriers that defanged the 15th Amendment. By 1918, poll taxes, literacy tests and grandfather clauses had closed Southern voting booths to African American men. Women’s suffrage would undermine that bigoted project.

Worse, the 19th Amendment might spur interracial solidarity among women, to the benefit of Republicans. Sen. James Reed, a Missouri Democrat, fretted about an alliance forming when “clamors go up from the dark sisters of the South that they are not being permitted to vote, and the sisters of the North who belong to a political party that feels it is losing votes down South get aroused.”

That is not to say there were no Southern supporters of the 19th Amendment. Ironically, they employed even more vicious arguments — yet were the very men whose help Wilson needed most to get the measure passed.

Sen. Kenneth McKellar of Tennessee said, “Any person who really wants white supremacy in the South can not better guarantee it than by the enactment of this equal-suffrage resolution.” He had made the calculation that with white women substantially outnumbering black women, the overall white vote would be expanded.

Not that black women would be voting anyway, since Jim Crow could also be applied to them. Sen. Joseph Ransdell of Louisiana reassured his colleagues that “the situation as to negro women can be handled as has been done with negro men for the past 25 years.” Ransdell added, “it is inconceivable that these conditions will be destroyed or even interfered with by permitting women to vote.”

James Vardaman, a Mississippi senator, favored playing the long game: passing the 19th Amendment, adding millions of white women to the rolls, then repealing the 15th Amendment and thus barring all “negroes, both male and female, from the politics of America.”

These statements — outrageous to modern ears — were uttered without eliciting the slightest condemnation in Congress. Instead, the backers of women’s suffrage silently counted votes and stuck blandly to praising female competence. White feminist leaders were little better, not denouncing congressional racism and instead banishing black women to the back of suffrage parades, hoping their presence would go unnoticed even as they won the ballot.

Supporters knew that every racist vote in favor of the 19th Amendment brought it closer. That still wasn’t enough. The amendment failed by two votes to gain the necessary two-thirds majority in the Senate in 1918. Not until the Republican Party gained a majority in 1919 did the 19th Amendment pass. And not until the Voting Rights Act of 1965 was the amendment enforced nationwide , with the endorsement of women then in Congress.

During the celebrations next year marking the centenary of the 19th Amendment’s ratification in August 1920, it will be worth recalling that though not everything in the United States is about race, sometimes race is more involved than meets the eye.