The story of a poor young woman, separated by prejudice from her husband and baby, is interwoven with tales of intolerance from throughout history.

When the Great War breaks out, brothers Roy and Monte Rutledge, each attending Oxford University, enlist with the Royal Flying Corps.

Barnstorming pilots Speed Condon, Bill Adams, and Eddie Smith travel the country with their manager, Alec Dugan, performing at fairs and air shows and hawking rides for the locals. But when Speed's rambunctious flying results in tragedy, he gives up flying in despair and guilt. Alec tracks him down and hopes to get him back on his feet and back in the air.

Two families, abolitionist Northerners the Stonemans and Southern landowners the Camerons, intertwine. When Confederate colonel Ben Cameron is captured in battle, nurse Elsie Stoneman petitions for his pardon. In Reconstruction-era South Carolina, Cameron founds the Ku Klux Klan, battling Elsie's congressman father and his African-American protégé, Silas Lynch.

World War I ace Dick Courtney derides the leadership of his superior officer, but he soon is promoted to squadron commander and learns harsh lessons about sending subordinates to their deaths.