Must I register a copyright with the government to receive protection?
No. You get protection as soon as you create a hard copy, or printed out or save it to your hard drive, but it’s minimum protection, such that if you can prove you’re the author, and the owner, and that it was infringed, you can sue somebody for copyright infringement. But, the maximum protection, and the enhanced leverages obtained by registering it at the U.S. Copyright office, and a registered copyright is a significant intellectual property asset because it lasts your life plus 70 years as a personal asset, or 95-120 years as a corporate asset.