Hiram Rhodes Revels arrived on Capitol Hill to take his seat as the first Black member of the U.S. Congress in 1870. But first, the Mississippi Republican faced Democrats determined to block him.

The Constitution requires senators to hold citizenship for at least nine years, and they argued Revels had only recently become a citizen with the 1866 Civil Rights Act and the 14th Amendment. Before that, the Supreme Court had ruled in its 1857 Dred Scott decision that Black people weren’t U.S. citizens.

This technicality wasn’t actually their main issue with Revels. At the time, the Democrats were the party of white southern men, and they simply didn’t want any Black men in Congress.

In any case, their bad faith legal argument didn’t hold up. Revel’s fellow Republicans argued he was born a free man in the United States and had lived there all his life. Dred Scott was a bad decision that should’ve never been made, which the Civil Rights Act and 14th Amendment had sought to redress, they argued. Just because the law had only recently recognized Black men’s citizenship didn’t mean he was a “new” citizen.

“Mr. Revels, the colored Senator from Mississippi, was sworn in and admitted to his seat this afternoon,” reported The New York Times on February 25, 1870. “Mr. Revels showed no embarrassment whatever, and his demeanor was as dignified as could be expected under the circumstances. The abuse which had been poured upon him and on his race during the last two days might well have shaken the nerves of any one.”

Revels took his oath only five years after the Civil War. Over the next decade, 15 more Black men took their seats in the House and Senate, including men like South Carolina Congressman Robert Smalls who were previously enslaved.

“It really does reflect what a revolutionary period Reconstruction was,” says Gregory Downs, a history professor at the University of California, Davis. Congress had ordered the Army to register Black southern men to vote in 1867. “In a series of a few months, you had people…in South Carolina and other places who had been slaves as recently as two or three years before now participating, now voting and even being elected to serve to remake the Constitution.”

The large population of formerly enslaved people meant that there were many more Black voters in the south than the north (and actually, some northern states didn’t enfranchise Black men until after the southern states). Black men elected Black representatives and white Republicans locally and at the state level, which led to representation at the federal level.

But the people who had objected to Revels joining the Senate were still mad, and it was only a matter of time before backlash struck. In the 1870s, organizations like the White League and the Red Shirts began terrorizing and intimidating Black men so they wouldn’t vote and participate in government.

Because of these tactics, “the height of statewide Black power crests in the middle of the 1870s,” Downs says. “But what does remain in place from the 1880s into the mid-1890s is an enormous amount of Black local political power centered in the regions where Black people are a sizable majority.”

That too came under attack as Jim Crow laws, poll taxes and other racist measures spread throughout the south. “The 1890s and early 1900s is where you get the laws that aim to permanently exclude virtually all Black voters from participating,” Downs says. “The final Black congressman from the south is George White who gives his farewell address, the phoenix speech, in 1901.”

After White, there were no more Black Congress members from the original 11 Confederate states until 1973, when Andrew Young, Jr., of Georgia and Barbara Jordan of Texas (both Democrats) took their seats. Jordan’s election was particularly significant as she came just after New York’s Shirley Chisholm became the first-ever Black Congresswoman in 1969—a full century after emancipation.