No such thing as “international copyright”
The earliest case on copyright law dates to the year 561 over the ancient Irish manuscript, the Cathach of St. Columba. But the first proper copyright law is the Statute of Anne, the Copyright Act 1709, named after Queen Anne, monarch of Great Britain at the time.
In 1886, the Berne Convention was established to recognize copyrights among nations. Perhaps the most convenient issue about the Berne Convention is that an artist or author does not have to register or claim for copyright – it is automatically achieved when the work is recorded.
The United States signed the Berne Convention only in 1998. The United States and some Latin American countries had entered into the Buenos Aires Convention in 1910. This convention required a copyright notice on the work, such as “All rights reserved.” Some other countries chose to sign The Universal Copyright Convention, drafted in 1952 by UNESCO. The World Intellectual Property Organization (WIPO) was created in 1967 to promote the protection of copyright throughout the world. WIPO is a specialized unit of the United Nations and more than 180 nations have signed up to it.
Still, there is no such thing as an “international copyright.” Each country has its own copyright laws. However, most countries offer protection to foreign works under international treaties.
Generally copyright lasts for 50 years after the death of the creator, although some countries allow only 25 years. For anonymous works copyright will be 95 years from publication or 120 years from creation, whichever is shorter.
You can also choose to have copyleft on your work; that is when you make it available for free.
Copyright law does not protect sightings of Elvis – unless you have a photo to prove it.