In simplest terms, for works created now:

• for a single author, copyright lasts for the remaining life of the author plus 50 more years;

• for an organization, copyright lasts for 75 years from the date of publication, or 100 years from the date of creation, whichever occurs first.

the original date of the work:

• prior to 1909,
• between 1909 and 1977,
• between 1978 and 1988, or
• since 1989;

• a single author,
• an entity (such as a business),
• a mixture of people and entities (and how many of each),

• US citizens or residents,
• citizens or residents of signatories of the Berne Convention, the Universal Copyright Convention,