( CNN ) -- The new Steven Spielberg blockbuster `` Lincoln '' focuses on the final months of the U.S. president 's life as he tries to find a way to end the Civil War and unite the country . Now , the document Lincoln signed that officially started the war is up for sale , valued at nearly a million dollars . The one-page document , signed April 19 , 1861 , authorized the blockade of Southern ports , which , under international law , was an act of war . `` The action was bold and with great risk , '' said Nathan Raab , vice president of The Raab Collection , which is offering the document for sale at $ 900,000 . `` Lincoln was aware that the blockading of ports was an act of war . Some in his cabinet argued that a blockade would constitute recognition of the sovereignty of the Confederacy , something the North wanted to avoid . Lincoln was less interested in the legal definitions of 'war ' than in victory , and he approved it despite the objections . '' Go where Lincoln went . The Supreme Court later ruled the document as the official start of the Civil War , Raab said . It was April 12 , 1861 , when Confederate forces opened fire on Fort Sumter in Charleston harbor , South Carolina , initiating the hostilities between North and South . Three days later , Lincoln issued a proclamation that an insurrection existed , and he called out 75,000 men to put it down . Four days after that , on April 19 , he ordered the Southern port blockade . `` I hereby authorize and direct the Secretary of State to affix the Seal of the United States to a Proclamation setting on foot a Blockade of the ports of the States of South Carolina , Georgia , Alabama , Florida , Mississippi , Louisiana , and Texas , '' the document states . Lincoln 's signature is at the bottom , `` firm and bold , exactly as you 'd like to see , '' Raab said . Lincoln 's lessons for Obama . The privately owned document has been on exhibit for several years at public institutions across the country , including the National Constitution Center and the Abraham Lincoln Presidential Museum and Library . `` It 's been passed down to posterity quite well , '' Raab said . `` It 's survived the 150 years in good shape . '' The Spielberg movie and the 150th anniversary of the Civil War have generated a lot of interest in the document and in Lincoln items in general , Raab said . Spielberg film brilliant , reviewer says . The document went on sale Tuesday night and will go to the first person who meets the asking price . Potential buyers can make contact with the seller through the Raab Collection 's website , by phone , or in person .
The document authorized the blockade of Southern ports . The Supreme Court ruled the document to be the official start of the Civil War . The privately owned document has been on public display for several years . It will be sold to the first bidder who offers the asking price of $ 900,000 .