PHILADELPHIA (AP).- A document signed by President Abraham Lincoln ordering Union blockades of Confederate ports, marking the official start of the Civil War, is for sale.

The Raab Collection in Philadelphia said Tuesday it is selling the document, which it calls one of the most important in American history. The asking price is $900,000.

Lincoln's proclamation is dated April 19, 1861 — a week after the first shots of the conflict were fired at South Carolina's Fort Sumter. After the Civil War ended in 1865, the U.S. Supreme Court in an opinion ascribed Lincoln's April 19 blockade order as the official beginning of the war.

"This action was bold and with great risk," said Nathan Raab, vice president of The Raab Collection. "Lincoln was aware that the blockading of ports was an act of war."

Some of the president's cabinet objected the move, saying it could be seen as a de facto recognition of the Confederate States of America as a sovereign nation because countries do not blockade their own ports. Lincoln, however, "was less interested in the legal definitions of 'war' than in victory, and he approved it despite the objections," Raab said.

The document, which has been owned by a private collector who wishes to remain anonymous, was exhibited recently at museums including the National Constitution Center in Philadelphia and the Abraham Lincoln Presidential Museum and Library in Springfield, Ill.

The single-page manuscript authorizes Lincoln's 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 seal was affixed to the blockade proclamation announced that day, effectively declaring war on the Confederacy.

Between 1861 and 1865, the Union Navy blockade successfully crippled the Confederate economy by largely preventing the import of supplies and ammunition and the export of cotton and other trade goods to and from ports along 3,500 miles of the Atlantic and Gulf coasts.

The strategy, part of Gen. Winfield Scott's so-called Anaconda Plan, is seen by historians as a key factor in the Union's victory.




Copyright 2012 The Associated Press.