France was the cradle of the modern idea of democracy. French troops were vital to America's victory in the War of Independence and Paris led the world in science, medicine and the arts. And as McCullough has written, the city was irresistible to the new citizens of a new nation.
David McCullough: They came here in the droves. They were here in order to improve themselves and to go home and thereby improve their country.
They were the first wave of innocents abroad, who began arriving in Paris just 50 years after Independence. Writers, artists, medical students.
David McCullough: They couldn't quite adjust to how old everything is. When they were looking at Notre Dame they were looking at a building that was begun before Columbus ever sailed.
Paris had grand boulevards. Breathtaking parks. Great universities. All the things young America didn't have.