Definition:
Art Nouveau
The time period of 1890 to 1914 are considered the years of the Art Nouveau period.
According to the [link url=http://www.nga.gov/feature/nouveau/exhibit_intro.shtm]National Gallery of Art[link]: "Art Nouveau was a concerted attempt to create an international style based on decoration. It was developed by a brilliant and energetic generation of artists and designers, who sought to fashion an art form appropriate to the modern age."
