It will be understood that the revenue of the government was altogether unequal to the vast demands upon it. Taxation was increased, and, in 1862, the government began the issue of its own paper money. The backs of the bills being printed in green ink, these bills were known as "greenbacks." They were made a legal tender, despite considerable opposition to the measure. The law gave any person owing a debt, no matter if contracted in gold and silver, the right to pay the same with greenbacks. Since it is impossible to regulate the value of money except by the law of supply and demand, the bills, as compared with gold, depreciated a good deal in value. The act of February 25, 1862, authorized the issue of $150,000,000, and further issues were made on June 11, 1862, and March 3, 1863. The depreciation of greenbacks was such that the price of gold averaged 2.20 throughout 1864, and at one time reached 2.85. In other words, a greenback dollar was worth only thirty-five cents. Another method of raising money was through the sale of bonds, of which many millions were issued. To encourage their sale, the National Banking System was established in 1863. This required all banks that issued currency to deposit a slightly larger amount of bonds in Washington. Thus the banks were compelled to help the government by loaning it money. [Illustration: THE BATTLE OF MALVERN HILL, JULY 1, 1862 Malvern Hill was a very strong position taken by General McClellan in his retreat before the army of Lee. General Lee made furious and repeated assaults upon this well-nigh impregnable position, each time to meet an inevitable repulse, and in the end a defeat accompanied by severe losses, which necessitated his withdrawal to Richmond.] CHAPTER XVII. ADMINISTRATION OF LINCOLN (CONTINUED), 1861-1865. WAR FOR THE UNION (CONTINUED), 1863. The Military Situation in the West--Siege and Capture of Vicksburg--The Mississippi Opened--Battle of Chickamauga--"The Rock of Chickamauga"--The Battle Above the Clouds--Siege of Knoxville--General Hooker Appointed to the Command of the Army of the Potomac--His Plan of Campaign Against Richmond--Stonewall Jackson's Stampede of the Eleventh Corps--Critical Situation of the Union Army--Death of Jackson--Battle of Chancellorsville--Defeat of Hooker--The Second Confederate Invasion--Battle of Gettysburg--The Decisive Struggle of the War--Lee's Retreat--Subsequent Movements of Lee and Meade--Confederate Privateering--Destruction of the _Nashville_--Failure of the Attacks on Charleston--The Military Raids--Stuart's Narrow Escape--Stoneman's Raid--Morgan's Raid in Indiana and Ohio. There were now such immense armies in the field and military operations were conducted on so vast a scale that the reader must carefully study the situation in order to gain an intelligent idea of the progress of the momentous events. We will give our attention first to operations in the West. THE SITUATION IN THE WEST.