Viable chemical photography dates back to the 1820s when the first permanent image, produced by Nicéphore Niépce, appeared in 1825. The pictures, however, took forever to develop, so Niépce worked with a colleague, Louis Daguerre, to experiment with silver compounds (a mixture of silver and chalk was found to darken when exposed to light by Schultz in 1724).
Niépce died less than a decade later, so Daguerre continued working on the project and unveiled the daguerrotype in 1837, taking the first picture of a person in 1839, though it took several minutes to take the picture on the long exposure.
William Fox Talbot refined the process, having discovered a way of fixing silver compounds earlier than Daguerre, making photographic portraits available to the general population.
The following proceses were used for creating photographs in the 1800s:
Calotype: Uses silver nitrate on salt paper to create negative images
Cyanotype: Exposes coated paper to UV light to create blueprints
Collodian: Most popular method of the mid-late 1800s, only taking a few minutes but requiring a portable dark room with the photographer.
The first permanent photograph in colour was taken by James Maxwell in 1861. To do this, they used three separate cameras, each having a colour filter.