Happy birthday Louis-Jacques-Mandé Daguerre (11/18)! Daguerre invented the daguerreotype photography process in France and introduced it to the French public in 1839. Months later daguerreotypes made their way to America, where an eager public clamored for the miraculous “mirror with a memory.” Daguerreotype images are produced by sensitizing a polished silvered copper plate with iodine vapor, and then exposing the plate to light. The image is developed over hot mercury, fixed, and rinsed. By 1850 American daguerreotypists were producing over three million daguerreotypes each year and New York City boasted more than 70 daguerreotype studios. Daguerreotype portraits were particularly popular thanks to their affordability (today’s equivalent of two to five dollars). William Jay, the youngest son of John Jay, was an ardent abolitionist and pacifist. This daguerreotype portrait, taken by an unknown photographer, captures Jay’s intensity and kindness.