The series is based on the book Destiny of the Republic by Candice Millard.

Offerman (pictured, left) plays Chester Arthur and Gilpin (pictured, right) plays Crete Garfield.
Offerman appeared last year as Bill in HBO hit The Last of Us, for which he won a Primetime Emmy Award for Outstanding Guest Actor in a Drama Series. The actor also appeared in the second season of FX series Fargo, FX miniseries Devs on Hulu and in Hulu's Pam & Tommy as Uncle Miltie.
Gilpin is best known for her role as Debbie "Liberty Belle" Eagan on Netflix's women's wrestling drama GLOW. She recently appeared in Three Women, which was originally intended for Showtime but ended up at Starz. Gilpin also played roles in the Peacock limited series Mrs. Davis, the Starz limited series Gaslit starring Julia Roberts and Sean Penn and the Showtime comedy series Nurse Jackie.
Garfield was president in 1881 and was assassinated later that year, after previously serving nine terms as a congressman. He was elected as a senator but declined when he became president, even though he had not sought the office. He was shot by Guiteau, who felt he had played a major role in Garfield's election.