The Civil War Gold Hoax
On the morning of May 10th 1864 a flurry of telegraphs flew between Washington D.C. and New York. The morning paper New York World, among others, published an article declaring that Lincoln requested 400,000 more troops for the Union army.
“I, Abraham Lincoln, President of the United States, by virtue of the power vested in me by the Constitution and the laws, have thought fit to call forth, and hereby do call forth, the citizens of the United States between the ages of eighteen and forty-five years to the aggregate number of 400,000, in order to suppress the existing rebellious combinations and to cause the due execution of the laws. And furthermore, in case any State or number of States shall fail to furnish by the fifteenth day of June next their assigned quotas, it is hereby ordered that the same be raised by an immediate and peremptory draft." 
Upon hearing of this publication Secretary of State, William H. Seward, promptly telegraphed Major Thomas T. Eckert asking “Is it genuine?” At the same time a telegraph from New York questioned the papers claim “A proclamation by the President, countersigned by you, and believed to be spurious, has appeared in some of our morning papers… ” to which Seward replied “The paper is an absolute forgery.” Lincoln himself weighed in on the events.
“Whereas, there has been wickedly and traitorously printed and published this morning in the New York World and New York Journal of Commerce, newspapers printed and published in the city of New York, a false and spurious proclamation purporting to be signed by the President and to be countersigned by the Secretary of State, which publication is of a treasonable nature, designed to give aid and comfort to the enemies of the United States and to the rebels now at war against the Government, and their aiders and abettors, you are, therefore, hereby commanded forthwith to arrest and imprison in any fort or military prison in your command the editors, proprietors, and publishers of the aforesaid newspapers, and all such persons as after public notice has been given of the falsehood of said publication, print and publish the same, with intent to give aid and comfort to the enemy, and you will hold the persons so arrested in close custody until they can be brought to trial before a military commission for their offense.” 
The arrests of the paper’s editors and the seizing of the presses were promptly ordered, specifically the Independent Telegraph Company. Major- General John Dix seemed hesitant to carry out the orders saying that the editors of the World put out a reward for information on the author of the article, and other Papers printed the article but did not deliver any copies upon discovering the article. “I shall execute it (the orders to arrest) unless the foregoing information shall be deemed sufficient by the President to suspend it until my investigation is concluded.”
Secretary of War Edwin Stanton sent back a terse reply “You were not directed to make any investigation, but to execute the President's order; the investigation was to be made by a military commission. How you can excuse or justify delay in executing the President's order until you make an investigation is not for me to determine.” Dix replied that he had been investigating the publishing of the paper before Washington’s telegraph had arrived.
“The investigation was made by me as commanding officer of the department before the President's order was received, as my dispatch showed. There has been none since. I understood the President's orders as commands to be executed, and there has been no unnecessary delay in the execution. The telegraphic offices were seized as soon as my officers could reach them.” It seemed Stanton’s information lagged a bit behind as the next telegraph to Dix read, “Your dispatch in regard to the probable origin of the forged proclamation is just received. I am satisfied the publishers of the World and Journal of Commerce had no knowledge of it. I shall, therefore, suspend the order as to them, but shall keep possession of their printing offices until you otherwise direct.” 
Further telegraphs coordinate preventing of the stories circulation and rounding up copies that escaped to other cities. The government was horrified to find that the paper had been published on a “steamer day”. Meaning that ships carrying copies of the offending article had left port to various destinations aboard various steam vessels, and the government scrambled to get ahead of their arrival.
Finally the telegraph from Dix relaying the capture of the perpetrator came through. “I have arrested and am sending to Fort Lafayette Joseph Howard, the author of the forged proclamation. He is a newspaper reporter, and is known as ‘Howard, of the Times.’ He has been very frank in his confession-says it was a stock-jobbing operation, and that no person connected with the press had any agency in the transaction except another reporter, who took manifolds and distributed the proclamation to the newspapers, and whose arrest I have ordered. He exonerates the Independent Telegraph Line, and says that publication on a steamer day was accidental.” Lincoln sent a reply back through Stanton.
“He directs me to say that while, in his opinion, the editors, proprietors, and publishers of The World and Journal of Commerce are responsible for what appears in their papers injurious to the public service, and have no right to shield themselves behind a plea of ignorance or want of criminal intent, yet he is not disposed to visit them with vindictive punishment; and hoping they will exercise more caution and regard for the public welfare in future he authorizes you to restore to them their respective establishments.” 
The previously arrested editors and their presses were released from military control and this concluded the fiasco. Howard spent 3 months in prison for his crime. His goal had been to imply the war was not going well for the Union and take advantage of the fall out of said news in the stock market. The stunt caused the value of gold to increase by 10% as the New York Stock Exchange took a hit and investors sought a more physical asset. You can read the full transcript in the official record starting here.