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.
"Ella Enchanted" by Gail Carson Levine was published in 1997, so the copyright date would be 1997.
Each issue would have its own copyright information; the first issue would be 2002.
The date listed in the copyright notice of a book is usually the date of first publication. Sometimes books are revised for later printings, however, and in such cases the date of first publication of the revised edition may be used. So, if a book was originally published in 2010 but revised in 2011 the copyright notice date for the revised edition may be 2011.