• its author died before 1954;
• the death date of its author is not known, and it was created before 1904;
• it is an anonymous work, a pseudonymous work, or a work made for hire, and it was created before 1904.

The above provisions are contained in 17 U.S.C. § 303. See also this page for more information.

Toto dílo je volné také v zemích, jejichž právní řád chrání majetková autorská práva po dobu života autora a 80 let po jeho smrti.

 Note that a few countries have copyright terms longer than 80 years: Mexico has 100 years and Jamaica has 95 years. This image may not be in the public domain in these countries, which moreover do not implement the rule of the shorter term.