The show is set in the days leading up to Lincoln's assassination, which occurred while he and Mary were watching Our American Cousin at Ford's Theatre.

The show portrays Mary as someone who longs to live a life away from politics and be a cabaret performer, while Lincoln uses her as a beard to hide his sexuality, and is often away from home dealing with the issues of the Civil War, leaving her alone in the White House.

[17] Amelia Merrill of the New York Theatre Guide emphasized the campy, irreverent nature of Oh, Mary!, calling it both absurd and heartwarming.

She pointed out how Escola's reinterpretation of Mary Todd Lincoln, though not historically accurate, explored the First Lady's mental health struggles through comedy.

"[19] Howard Miller of Talkin' Broadway emphasized the show's success in balancing a "queer-infused raucous, farcical, campy" energy while maintaining emotional depth beneath its absurdity.