It is not necessary for the work to be completely original. Works may be combined, adapted, or transformed in new ways that would make them eligible for copyright protection. Verbatim use is not considered original. Reference to the original work that is used to discuss a new concept would be considered original, however. Creativity need only be extremely slight for the work to be eligible for protection.
Facts are in the public domain.
Words, names, slogans, or other short phrases also cannot be copyrighted. However, slogans, for example, can be protected by trademark law. Works created by federal government employees as part of their official responsibility. It is a common misperception that state employees and contractors performing work on behalf of the federal government cannot copyright their work. Unless it is explicitly stated in the contract between the government and a contractor, federal government contractors are permitted to copyright their works as can state employees.