‘Would Washington have ever been commander of the revolutionary army, or President of the United States, if he had not married the rich widow of Mr Custis?’ asked John Adams. The answer, says Flora Fraser, is no. We like to see our ‘men of destiny’ as striding the world alone before stepping onto the customary plinth, so some might find it inconvenient to consider the role, in George Washington’s glorious career, of America’s first First Lady.