An original copy of the 1916 Proclamation is expected to fetch nearly £200,000 at a Sotheby's auction in New York this Thursday.
"The document is one of approximately 50 extant copies of the founding charter of Irish nationhood, and has survived in an extraordinary state of preservation," Sotheby's said.
"Of the utmost rarity, the Proclamation is undoubtedly the most important and iconic document in the history of the Irish Nation, containing the first aspirations of the Republic," Sotheby's added.
"With its emphasis on freedom of the individual, 'religious and civil liberty, equal rights and equal opportunities to all its citizens' and a government in the form of a republic, this 20th-century document finds its antecedent in none other than the American Declaration of Independence.
"Though the Rising failed, the principles of the Proclamation to varying degrees influenced the thinking of later generations of Irish politicians."
The document will be part of a fine art and manuscript sale in Manhattan this week.
In April, a private collector scooped a rare signed copy of the 1916 Proclamation of Independence for €360,000 at the third annual Independence auction.
Bids for the Proclamation document entitled 'Poblacht Na hEireann -- The Provisional Government of The Irish Republic To The People of Ireland' -- opened at €250,000 and sold within one minute to a mystery buyer bidding over the phone at the Adam's & Mealy's auction in Dublin.
Signed by the Irish rebel leader Sean McGarry, it sold for €30,000 short of the record €390,000 paid in 2004 for one of the 50 surviving copies of the original 1,000 copies of the Proclamation -- the founding document of the Irish Republic that was printed under the protection of the Citizen Army on Easter Sunday 1916.
The Proclamation was read outside the GPO at the start of the Easter Rising by Padraig Pearse on Easter Monday and was signed by McGarry.