The artwork titled "Why He Cannot Sleep" is a detailed illustration from Harper's Weekly, dated July 7, 1866. It depicts a man lying in bed, unable to sleep. His expression is weary, and he clutches the bedding. Beside him is a skeleton with one arm resting on the man’s shoulder. A figure, a woman with long, flowing hair and a crown, stands beside the bed, pointing outwards. The background reveals a window with a moonlit scene outside and a vision of battle or turmoil. The overall tone is dark.