She Spoke to the Dead. They Told Her to Free the Slaves.

In 1850s Vermont, Achsa Sprague swore that the spirits who miraculously helped her walk again also possessed her with a crucial mission: freeing every soul in America.

Illustrations by Fan Pu | Edited by Julia Métraux

A woman with dark, glossy hair and sharp cheekbones stood confidently under a tent with her eyes closed. About a thousand convention-goers waited for her to speak, standing patiently or sitting on the grass. Five full minutes ticked by on the timepiece the organizers had provided to keep the convention schedule on track. Still she stood there with her eyes closed, and the crowd waited.

It was Friday, June 25, 1858, and the first day of the Rutland Free Convention had already been momentous, and hot. The massive tent was set in a green field on the outskirts of Rutland, Vermont, then a city of about 7,500 people, and it was visible from half a mile away. Booths surrounded the tent, selling lemonade, root beer and soda pop. “The whole aspect of the locality was precisely that of a Country Fair,” a New York Times reporter wrote. The convention-goers’ only other relief from the heat was ice water poured out of faucets set into two casks that…