WASHINGTON — The National Archives announced yesterday that it has uncovered in its stacks a hand-written note sent by Abraham Lincoln to one of his top generals four days after the battle of Gettysburg, at the height of the Civil War.

The note, dated July 7, 1863, was sent to General Henry Halleck urging that the defeated Confederate Army commanded by General Robert E. Lee be pursued in the hopes of quickly ending the war.

The six-line, two-sentence note reminds Halleck, then the Union army’s general in chief, that the besieged Confederate city of Vicksburg, Miss., appears to have fallen, and that if General George Meade’s Union Army of the Potomac can destroy Lee, “the rebellion” may be over.

Archives officials said the note is significant because it shows Lincoln’s momentary optimism that the war would end quickly — short-lived when Lee’s army escaped across the Potomac River a few days later. The war went on for another year and a half, ending in the spring of 1865.

The contents of the note had been known to historians, archives officials said at a morning news conference. The text had been forwarded by Halleck to Meade in a telegram that was preserved in official government war records. But the hand-written note itself was discovered May 21 in the archives’ downtown building by an archivist doing research for a film crew.