Book excerpt: Faced with failing health and financial ruin, the Civil War's greatest general and former president wrote his personal memoirs to secure his family's future - and won himself a unique place in American letters. Devoted almost entirely to his life as a soldier, Grant's Memoirs traces the trajectory of his extraordinary career - from West Point cadet to general-in-chief of all Union armies. For their directness and clarity, his writings on war are without rival in American literature, and his autobiography deserves a place among the very best in the genre.