An 1858 manuscript acquired by Yale's Beinecke Rare Book & Manuscript Library in 2009 has been confirmed to be the oldest prison memoir ever written by an African-American.

The 304-page, book-length manuscript titled 'The Life and Adventures of a Haunted Convict' was written under a pseudonym 'Robert Reed'.

The manuscript details the author's experiences during his imprisonment at both the New York House of Refuge and later in New York's Auburn State Prison from the 1830s till 1850s. The narrative was aimed at exposing the brutal punishments in prisons that included whippings and shower baths, where chilled water is poured over the prisoner, until the guard decides to stop.

Reed described the horizontal black-and-white striped uniform that originated at the prison as 'streaked clothes of shame and disgrace.'

Caleb Smith, English and American studies professor identified its true author as Austin Reed, a black man born in upstate New York.

"Finding any new text by an African-American author of the 19th century is significant, but this memoir has so much to say about captivity, freedom and human rights," Smith said in a statement. "It is a truly remarkable discovery." Smith is currently preparing the manuscript for publication.

Of the many events described in the manuscript, Reed's account of a confrontation with a warden catches attention.

"Stripping off my shirt the tyrantical curse bounded my hands fast in front of me and ordered me to stand around. Turning my back towards him he threw sixty seven lashes on me according to the orders of Esq. Cook. I was then to stand over the dreain while one of the inmates was my back in a pail of salt brine," abc news reports.

Experts called the manuscript a 'unique' and 'valuable' source because it provides insights in to the lives of African-American prisoners in antebellum America (between 1789 and 1860).

David Blight, Yale American history professor, called the finding 'a revelation.'

"Nothing quite like it exists," said Blight, director of the Gilder Lehrman Center for the Study of Slavery, Resistance, and Abolition. "Reed is a crafty and manipulative storyteller, and perhaps above all he left an insider's look at the American world of crime, prisons and the brutal state of race relations in the middle of the 19th century."