1752.
Julius Caesar has never been subject to copyright.
The first copyright law went into effect in 1710.
It is either the date of creation or the date of first publication.
No, a copyright date is the first date of publication and an imprint date can be many years later, e.g., a later edition based upon the original copyright date.
Welcome to the Dead House is copyright 1992.
The date on a copyright notice will indicate one of two things. Either the when copyright became effective (when the work ewas initially finished) or first date of publication.
When first published in 1810
The first appearance of Archie Andrews in comic books was Pep Comics #22, on December 22, 1941 and that would also be the copyright date.
The first book is copyright 1924; later books in the series have different dates.
The Adventures of Huckleberry Finn was first published in the United States in 1885, so the copyright date would be around that year.
The Magic Finger by Roald Dahl was first published in 1966, so the full copyright date would be 1966.
Each issue would have its own copyright information; the first issue would be 2002.