Julian West is a 30-year-old educated aristocrat who relies on a subterranean sleeping chamber to cure his severe insomnia. Having never worked, he lacks sympathy for the striking working classes and resents the delays they cause to the construction of his new home. Upon waking in the year 2000, he serves as an inquisitive student, trying to comprehend the newly reformed socialist society and his place within it.

Doctor Leete is a retired physician living in the utopian Boston of the year 2000. Acting as Julian West's host and intellectual guide, he patiently answers his guest's myriad questions about the new society. He firmly believes in the rationality of the 20th-century socialist system and frequently criticizes the selfish capitalism of the 19th century.

Edith Leete is the daughter of Doctor and Mrs. Leete, living a comfortable life in the year 2000. She serves as an emotional anchor for Julian West, comforting him when the shock of his time travel overwhelms him. She possesses a serene frankness, enjoys visiting the ward distribution centers, and harbors a deep romantic fascination with the 19th century.

Mrs. Leete is the wife of Doctor Leete and mother to Edith Leete. She shares meals with her family and their time-traveling guest, providing a quiet, welcoming presence in the household while her husband and West discuss politics.

Edith Bartlett is a beautiful, wealthy young woman engaged to Julian West in 1887. She shares her fiancé's upper-class anxieties regarding the ongoing labor strikes, which continue to delay the construction of their future home and threaten their comfortable way of life.

Sawyer is Julian West's trusted African American servant in 1887 Boston. He attends to West's daily needs and holds the critical responsibility of reviving his employer from mesmerism-induced slumbers each morning.

Doctor Pillsbury is a 19th-century mesmerist whom Julian West employs to cure his insomnia. He utilizes animal magnetism therapies to put West into a deep suspended trance so he can sleep through the city's noise.

Mr. Barton is a preacher in the year 2000 who broadcasts his sermons to over 150,000 subscribers. He uses his platform to compare the moral failings of the 19th century with the natural goodness he sees flourishing in the new social order.

Mr. Bartlett is Edith Bartlett's father in 1887 Boston. As a wealthy man, he views the working-class demands as a threat to societal order and contemplates fleeing the country if the strikes escalate.