1) In the mid-19th century, competing photographic technologies like the daguerreotype and calotype emerged, making personal photography accessible to the public for the first time.
2) Matthew Brady and other American photographers established portrait studios using the daguerreotype process, popularizing photographic portraiture among celebrities and common people alike.
3) By the 1850s, photographic portraiture had become standardized and industrialized, with "picture factories" mass producing portraits using specialized assembly-line techniques to complete the process in under 15 minutes.