Once an Eagle is a 1968 war novel by American author Anton Myrer. The novel takes place between the 1910s and 1960s, and covers many of the United States' military involvements during that period. Once an Eagle tells the story of Sam Damon, career Army officer, from his initial enlistment as a private to his rise to general officer rank. Damon is an honorable soldier who rises in rank by success in field command, and cares for the welfare of his troops. His career is contrasted with that of another soldier, Courtney Massengale, who has no honor, no concern for his troops, and rises in rank through staff positions by cunning and political connections. As the two rise in the ranks together, they frequently clash in their views.