Incorporation is the process of legally registering a business as a corporation with the relevant government agency. For information about the registration process - and for information on searching registration records - see "Secretary of State Records."
You can look up the state in which a U.S. business is incorporated in the D&B Million Dollar Directory, or you can use the sources discussed in the Registration Records section of the "Secretary of State Records" entry. You can also use the sources in the Registration Records section to find out the other states in which a corporation is (or isn't) licensed to do business.
For information on how to get incorporation forms and how to file them, see "Forms."
Foreign Incorporation: If you want to incorporate a business in a foreign country, your best bet is to hire CT Corp, CSC or another company that specializes in foreign incorporation.
For information on how to incorporate a business in a foreign country, a general summary of the law is published in the "Business Organizations" sections of each country's Martindale-Hubbell International Law Digest. More information is available in some of the Guides referenced in the separate entry for "Doing Business in Foreign Countries."