Painting is a very old art form also used by our ancestors in the form of cave painting. Watercolor has a long history from extremely old times. There are records found that watercolor was first used in late 1400s by western artists. These artists had their own secrete methods to formulate, prepare and applying techniques which they kept to themselves.
Much later in 18th century, the first paint manufacturer opened shop in major European cities where color pastes were made available along with the basic pigments. Soon after that dry clumps cut out of dry watercolor paints were made available for artists. Artists had to first grind these dry clumps with water to make it usable.
In late 18th century, watercolor came in sets with porcelain pans of moist watercolors that were comparatively cheaper and affordable for general public.
Winsor Newton was the first to introduce Glycerin- softened formula moist cakes in 1835. Later Winsor & Newton modified their original moist cake formula into semi-liquid formula for metal tubes.
Because of this new availability anyone can paint with these readily available watercolors that gave birth to various professionals as well as armature artists!
http://www.watercolorpainting.com/history.htm