The first photographic imaging process was introduced to the world by Louis-Jacques-Mandé Daguerre in Paris in 1839. This unique photographic system has been studied using two-dimensional (2D) and three-dimensional (3D) focused ion beam scanning electron microscopy (FIB-SEM) and transmission electron microscopy (TEM) to probe both historic 19th century and modern daguerreotypes. The electron microscopy images elucidate the process of image particle formation on the silver surface as a light-induced silver reduction initial step followed by a critical two-step silver mercury amalgam crystal development process. The first development step involves the chemical interaction between the gaseous mercury and the surface latent image silver clusters to form the initial amalgam seed image particle. The second development step continues to grow the initial amalgam seed to become a larger image particle able to scatter light. The initial silver and mercury amalgam seed image particle grows further through the amalgamation process. This continued growth involves the reaction of gaseous mercury and silver at the interface between the seed image particle and the silver surface, and silver from the sub/meso-surface that has migrated to the surface via atomic/mass transfer.