Volume One of a Civil War trilogy might be expected to take you as far as the Seven Days Battles, or at least halfway to Vicksburg. But ‘The Coming Fury’ delivers only what it says on the tin. It mainly describes the run-up to the war, ending at Bull Run/Manassas, the first major battle, though not very major by later standards.

This presents quite a challenge to an author trying to write the definitive history of the war, each volume exceeding 400 pages. At that rate, Volume One could have been in danger of getting bogged-down in political debate, with so few action-scenes to leaven the mix, and the big question to be debated: was the war caused by slavery?

Catton disposes of this theory so smoothly that we wonder why people are still asking the question. ‘States Rights’ meant the right to form a separate nation, and hold on to the cotton revenues. The right to own slaves was a separate debate altogether, somewhat on the back-burner, since Lincoln had declared that he would not interfere with slavery where it already existed. For example, the British could not have considered intervening on the side of the south (which they almost did) if it meant fighting for slavery, which they themselves had abolished. That was why Lincoln suddenly had to turn the war into an abolitionist crusade almost halfway through.

There was also the irony that Lincoln’s government never actually declared war - because it would have meant recognising the Confederacy as a proper nation. And the further irony that it was the Confederates who declared war, but with no plans to invade the north; they would have been quite happy without a shot fired.

The first shots were actually fired in a curious stand-off that could not be described as a battle, but almost a ritual dance, when the commander of the Union garrison in Charleston harbour surrendered it to the Confederates through a ponderous exchange of face-saving messages. It is now that we first hear that elegant phrase “to avoid a needless effusion of blood” that would pop-up in every exchange between opposing commanders in the war. There was even a pantomime element, when a false surrender was made to a comic-opera colonel with a huge moustache who turned out to have no authority to negotiate terms.

That still leaves many long chapters to be devoted to the political scene, with the newly-ascendant Republican Party and the North-South split of the Democrats. As the recording angel, Catton has no choice but to chronicle every development, however insignificant, and to list every individual involved, however unmemorable. He generally gets round this with his limitless fund of odd little details and anecdotes, slotted into a potentially monolithic narrative. Seeing that a party conference could well occupy forty or fifty pages, he takes time off to describe someone’s hairstyle or explain why the acoustics in the hall were so bad. Even an unexpectedly bright comet (Thatcher’s) comes into the story, with the American people briefly reverting to a state of medieval superstition as they speculate on its portents.

Of course there is also plenty of room for critical analysis of the big themes, such as Robert E. Lee’s curiously indecisive reaction to the outbreak of war (wondering whether to retire to his farm), and the contribution of lawyer Ben Butler to the ending of slavery by declaring runaways to be ‘contraband property’ that he felt free to confiscate - and liberate.