In November 1865, eight months after the end of the Civil War, a group of African Americans formed a convention in Charleston, S.C., drew up a petition demanding their civil rights and sent it to Congress in Washington, D.C., reports the Washington Post.

“We the undersigned colored citizens of South Carolina, do respectfully ask … in consideration of our unquestioned loyalty [that in the] re-establishment of civil government in South Carolina, our equal rights before the law may be respected,” the handwritten document begins.

What followed were 3,740 signatures, then-Sen. Jacob M. Howard (R-Mich.) told his Senate colleagues after receiving the petition — on a document that was 54 feet long.

It was a striking appeal from the newly freed, and previously free, African Americans, asking that they not be forgotten in the country’s postwar reconstruction. Never displayed publicly before, it went on exhibit Friday at the Smithsonian’s National Museum of African American History and Culture.

“The petition is a real touchstone for the expectations and the will of … African Americans …[who saw] this moment in the county’s history as a new beginning,” said Katy Kendrick, exhibitions curator at the museum. It’s a “very powerful and very direct claiming of full rights of citizenship.”

The petition is part of a new exhibit of 175 objects at the museum entitled “Make Good the Promises: Reconstruction and Its Legacies.”

The exhibit covers the turbulent postwar era of Reconstruction as the vanquished Southern states sought to recreate prewar racial oppression, and African Americans fought, ultimately in vain, to prevent it. And it examines the legacy of that struggle today.