Final answer:
No, you do not have to register a piece of work to copyright it, but registering your copyright offers additional legal benefits.
Step-by-step explanation:
No, you do not have to register a piece of work to copyright it. According to the U.S. Copyright Office, copyright protection exists automatically from the moment the original work of authorship is fixed in a tangible form of expression. This means that as soon as you create a work, such as a book, song, or artwork, and it is recorded or written down, it is protected by copyright. However, registering your copyright with the U.S. Copyright Office provides additional legal benefits, including the ability to sue for infringement and the potential to receive statutory damages and attorney's fees if necessary.