From the intimate to the infamous, these pictures of US commanders-in-chief (and a few also-rans) capture moments of tragedy and hope at the heart of the White House

Is it any surprise that “photo op” is a phrase imported into British English from the United States? Of course it came from there, the land where the visual image sits right at the centre of the culture, with politics no exception. It was the Nixon White House that came up with it, specifically a press aide by the name of Bruce Whelihan. According to Washington legend, whenever the president was meeting a visiting dignitary, Richard Nixon’s hardball press secretary, Ron Ziegler, would turn to his underling with an order to summon the snappers. “Get ’em in for a picture,” Ziegler would say. Too polite to put it that way himself, Whelilan would clear his throat and announce to the ladies and gentlemen of the Washington press corps, “There will be a photo opportunity in the Oval Office.”) The photo op was born.

But if the term was new, the thing itself had been a part of US politics almost from the start. Just as Roman emperors sought to cast themselves in stone and Tudor kings commissioned the finest artists to capture their likeness, so American presidents moved fast to harness the new technology of the age, in order that the nation might see the men who governed them. The selection of photographs assembled here is made up of a series of striking images, but a couple are extraordinary less for what they show than for the fact that they exist at all.