How can I tell if content is U.S. copyright protected?

In most cases, any picture, material, text, information, quote, map, song or illustration that you personally did not create is U.S. copyright protected by the person who created and/or published the material. Any text or pictures found in a book, magazine or newspaper is U.S. copyright protected by the publisher, artist, photographer or another individual. Most information found on the Internet is U.S. copyright protected.