Hello, I am a student of American history and a significant portion of my master's thesis was about enslaved identities in the early republic, so I have read a lot of books about slavery. It's important to note that I don't feel there is a meaningful distinction between the history of American slavery and the history of the United States writ large. The books I've listed here are mostly academic histories with a bias towards "major" works that later scholarship needs to answer to. These are not the only books that matter, just the niche I can offer direction in.
Assume a blanket content warning: racism, coercion, rape, kidnapping, violence, murder.
Many Thousands Gone: The First Two Centuries of Slavery in North America, Ira Berlin Ira Berlin was probably the preeminent scholar on slavery in the United States, and his work outlines the shifting, composite nature of the institution instead of a terrible inevitability. Generations of Captivity is a shorter book that covers and updates a lot of the same material.
American Slavery, American Freedom: The Ordeal of Colonial Virginia, by Edmund Morgan To paraphrase Samuel Johnson: "Why do the loudest cries for liberty come from the mouths of slavers?" This is a book about the fundamental contradiction at the heart of the American republican project, written at the end of Morgan's long and distinguished career. Morgan explains how white radicalism came to depend on institutional racism in the years before independence. For reading on slavery and the American Revolution, you might also try Forced Founders by Woody Holton.
Reconstruction: America's Unfinished Revolution, 1863-1877, by Eric Foner I don't think you can or should read about slavery without reading about the end of slavery and the South's bitter hold on white supremacy. Foner was one of the original revisionist historians of the period, following in the footsteps of W.E.B. Debois's Black Reconstruction instead of the Dunning School. If you're interested in how white people in the North decided Confederate monuments were okay, Race and Reunion by David Blight is your book. If you just want to demolish the "states rights" myth, Apostles of Disunion by Charles Dew does exactly that.
Saltwater Slavery: A Middle Passage from Africa to American Diaspora by Stephanie E. Smallwood In the past several years documentation of the trans-Atlantic slave trade has been made increasingly available, from ships logs and manifests to names of vessels and routes. Smallwood's project is to give the captive a voice beyond lines in a ledger. See also Slavery and Social Death by Orlando Patterson.
Scraping By: Slavery, Wage Labor, and Survival in Early Baltimore, by Seth Rockman This is a book about the struggles of the poor in Baltimore before and after independence. But there is a wide and deep historiography about slavery and capitalism: Daina Ramey Berry's The Price for Their Pound of Flesh, Baptist's The Half has Never Been Told, Johnson's Soul by Soul, back to Time on the Cross, Conrad and Meyer, and Eric Williams's Capitalism and Slavery.
Narrative of the Life of Frederick Douglass, the shortest thing on this list, also the most readable things on this list, also totally free. David Blight wrote a long and affectionate biography of Douglass in 2018. Another famous slave narrative is Olaudah Equiano's. Zora Neale Hurston got a lot of press when Barracoon: The Story of the Last “Black Cargo” was just published a few years ago, and there are many extant interviews from with survivors of slavery from WPA oral history interviews done in the 1930s.