RICHMOND, Va.-- Letters written by Confederate Gen. Robert E. Lee and President Abraham Lincoln are headed to auction, revealing each man's deeply felt views as the Civil War divided the nation.

The letters will be up for bidding Friday at Sotheby's, the New York auction house, along with a trove of Civil War treasures that includes the opera glasses Lincoln carried into Ford's Theatre the night of his assassination. The glasses are expected to fetch up to $700,000.

The unsent Lincoln letter addressed to a citizen is notable for its scolding tone and the Lee correspondence because it lays bare the gravity of his decision to stand by his beloved Virginia as it bolted from the North. Lee casts Virginia's secession as a revolution.