This web resource gathers a list of some famous American visual artists. From Charles Schulz or Andy Warhol, to Diego Rivera, you get to read their biographies and view their work online.
A great variety of disciplines and schools are joined together: photography, painting, cartoon, pop art, muralism, etc. There are excellent examples for a better understanding of how art can be expressed in so many different ways, and it is also a good source for analysis on composition, media, techniques, expressive features, context, and the modern era, among others.