Copyright

Copyright
reference

What is it?

Legal definitions (from the U.S. Copyright Office except as noted)

U.S. Code Title 17 (an excerpt from Cornell University)

Copyright Basics -- an e-pamphlet from the U.S. Copyright Office explaining basic definitions.

what copyright is -- an excerpt from Copyright Basics

what works are protected -- an excerpt from Copyright Basics

what is not protected (see also exemptions such as sections 105 and 120) -- an excerpt from Copyright Basics

Historical origins -- by Dale C. Mead. An informative presentation from an interesting perspective. Dale Mead is an attorney and librarian currently employed as an Information Architect at Nortel Networks. See here for more about his work.

Look also at the earliest version of the US statute.

Does something have to be registered? No.
Does something have to provide notice? No.
What about fair use? It depends. See also the results of CONFU.
Are there grey areas? Yes . See also here for the very grey.
Can I find more on the web? Yes.

To a broader context

"Justice", composited from two works by Edwin Abbey (commissioned as work by the Commonwealth of Pennsylvania, for the state capitol building): one of a photo of the finished work in Harrisburg (© circa 1890); the other a scan of an engraving of Abbey's sketches (© 1921).