Although copyright is automatically granted at the moment the work is created in a tangible form, the United States has a system whereby creators can - and in some cases must - register their works with the United States Copyright Office. This registration is voluntary, but it provides significant advantages.

Copyright registration in the U.S. is important for several reasons. First, to file a lawsuit for copyright infringement in the U.S., the work must be registered. Second, if you register your work within a certain timeframe after its creation, and the work is infringed upon after this registration, you may be eligible for statutory damages of $150,000 and recovery of legal costs and attorney's fees. 

While the Berne Convention, which the U.S. is a part of, does not require registration for copyright protection, the U.S. legal system has maintained this requirement for certain aspects of copyright protection and enforcement, which sets it apart from many other countries.

It is for this reason that Safe Creative has included a wizard to send registered works in our platform to the US Copyright Office. The submission is voluntary and has a cost independent of the subscription (US government fees + management): https://www.safecreative.org/faq/the-u-s-copyright-office-registration.