The United States Patent and Trademark Office (USPTO) is the federal agency under the Department of Commerce and is responsible for granting U.S. patents and registering trademarks. Their website provides everything you need to know about patents, trademarks, and IP policy.
Important to note from the USPTO: "Since the rights granted by a U.S. patent extend only throughout the territory of the United States and have no effect in a foreign country, an inventor who wishes patent protection in other countries must apply for a patent in each of the other countries or in regional patent offices. Almost every country has its own patent law, and a person desiring a patent in a particular country must make an application for patent in that country, in accordance with the requirements of that country. Similarly, local laws apply to trademark, copyrights, and other forms of intellectual property in each jurisdiction."
Agency Websites: Some agencies maintain their own special search tools, so be sure to check their individual websites.
