Stage directions tended to become longer and more detailed during the nineteenth and early-twentieth century. O'Neill's fellow Irishmen Oscar Wilde and George Bernard Shaw both provided detailed instructions about the layout of the stage, and the dress, appearance and movements of the characters. There were two principal reasons for this. One was a desire on the part of these dramatists to control the production as much as possible. The playwright would have been present at some rehearsals but did not generally have any directorial role. He would therefore do all he could in the text to ensure that the play looked as he wanted it to look. In this, British and Irish playwrights were often influenced by German opera and, in particular, Wagner's concept of "the complete work of art."

The other main reason for detailed stage directions was an increase both in general literacy, particularly in play-reading. A large section of Shakespeare's audience could not have read his plays if they had wanted to, which is one of the principal reasons why the First Folio only appeared seven years after his death. O'Neill's plays, however, were read as well as watched. This is clear from the way in which the characters are described. In Anna Christie, for instance, Johnny the Priest is introduced at the beginning of Act 1 with the same attention to detail as a character in a novel.