Before the republic had a name, a mill on the Neponset River was already grinding chocolate. In 1764 a penniless Irish chocolatier and the Dorchester doctor who staked him made the first chocolate manufactured in America — and the name they settled on, Baker’s, is still on a green box in the baking aisle today, the oldest American grocery brand still on a shelf. Here is the story of a chocolate older than the country: the vanished founder, the chocolate girl borrowed from a Dresden gallery, the hard truth in its first century, and the sign over Dorchester that went dark for fifty-six years and was lit again.