The Mexican War, which found the two friends serving as lieutenants in the same infantry regiment, finally separated them in unexpected ways. An encounter with Captain "Butcher" Bent sent George and Orry into action on the Churubusco Road, where a shell fragment destroyed Orry's left arm and his dreams of a career. Not long after, news of the death of the senior Hazard called George home, because his mother, with sound instincts, could not trust George's older brother, Stanley, to be a wise steward of the immense family business. Soon after taking charge of Hazard's, George wrested control of the ironworks from his ambitious, irresponsible brother.

Amputation of Orry's left arm put him in a brooding, reclusive mood for a time. But as he trained himself to run the plantation and perform two-handed tasks with one, his outlook revived and the friendship with George renewed itself. Orry stood up as best man when George married Constance Flynn, the Roman Catholic girl he'd met in Texas while en route to Mexico. Then George's younger brother, Billy, decided he wanted to attend the Academy, while Orry, desperately seeking some way to save his orphaned young cousin Charles from a wastrel's life, persuaded him to seek an Academy appointment. The friendship of Charles Main and Billy Hazard, already acquainted, soon replicated that of the two old grads.

In the last decade of peace, many Northerners and Southerners, despite ever fiercer rhetoric, ever sharper threats from political leaders and public figures on both sides, remained personal friends. It was so with these two families. Mains came North, Hazards traveled South — though not without difficulties in each case.

George's sister, Virgilia, who had carried her passionate abolitionism across an invisible line into extremism, had nearly undone the friendship. During a Hazard family visit to the Main plantation, she'd met a slave belonging to the man who later married Orry's sister, Ashton. Virgilia encouraged the slave to run away. When he did, he succeeded.