In the spring of 1922, World War I veteran James Buckner is scraping by breaking horses and working part-time as a night watchman in Corinth.
Unexpectedly, Mike Stone, an old friend from Buckner's cavalry days, shows up. He says he's headed for South America, but Buckner suspects he's on the run from the law. Stone soon gets into a scrape that leaves a local policeman dead.
Buckner arrests his old friend, but before he can get him to trial, Stone is taken from his cell and murdered. Buckner is convinced that Corinth police chief Baxter Bushyhead is behind the killing of his friend.
Bushyhead is also behind most of the crime in Corinth, and Buckner swears to bring him down. With the help of the alcoholic Dr. Jeff Peck and black saloon-keeper Elroy Dutton, both World War I veterans, Buckner attacks Bushyhead where it will hurt most, in his gambling and bootlegging profits.
Veterans' Day reaches a powerful, explosive climax as Buckner challenges Chief Bushyhead, his gangster allies, and the Corinth Police Department.