Copyrighted or Not
To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries
Notice a few things:
-the words copyright, patent or trademark are never used
-the word "limited" is specified
-the exclusive Right is designed to promote progress
Some folks either do not understand this or choose to ignore it.
An example from the workshop I attended is the Boston Globe reprinting the Declaration of Independence last year. At the end, it says (c)2005 Boston Globe. Interesting because the Declaration is not copyrightable! That's true on two fronts, actually: 1) material printed by the federal government (or what would become same) are not copyrightable - so go ahead, steal away from the Census Bureau, e.g., and 2) even if it HAD been copyrighted, the item by now would have lapsed into the public domain. Remember the notion of "limited".
Another example is a realistic photograph taken of the Mona Lisa. It is not copyrightable because there is no creativity involved, though there is some skill. Now if the picture were distorted, or a mustache added, e.g., it might very well be copyrightable.
From the Copyright page: Mere listings of ingredients as in recipes, formulas, compounds or prescriptions are not subject to copyright protection. However, where a recipe or formula is accompanied by substantial literary expression in the form of an explanation or directions, or when there is a combination of recipes, as in a cookbook, there may be a basis for copyright protection.
Copyright law has changed several times in the 20th Century and it can be tricky to ascertain whether some items are still under copyright or in the public domain. I learned that, due to some quirks in the law that expired in 2003, an unpublished work of Mark Twain, written in 1876, and published in the Atlantic Monthly in 2001, 91 years after the author's death, doesn't lose its copyright until 2048! You can pay the Copyright Office $150 per hour to check the copyright status, or your can try to search the copyright database yourself. You may discover that only part of the item - the introduction, or the annotation, e.g. - is under copyright.