Anderson utilizes a first-person narrative. The fourteen-year-old protagonist, Mattie, swiftly provides readers with details about Philadelphia and the epidemic.

The title "Fever 1793" was chosen by Anderson because the narrative unfolds during the devastating yellow fever epidemic in Philadelphia in 1793. Set in the post-Revolutionary period, the story delves into universal themes of friendship and mortality. As Mattie grows older, she learns about perseverance, hope, and self-reliance.

Mattie faces conflict with her mother, struggles with her changing body, and dreams about her future when she learns of her childhood friend Polly's death. Shocked, she has little time to mourn as she helps her mother with the coffeehouse customers. Uncertain about what caused Polly's death, Mattie and her family start hearing about yellow fever but quickly dismiss the warnings as overly pessimistic.

In the first chapter, readers learn about Mattie's crush on Nathaniel Benson. Nathaniel appreciates Mattie's sharp wit and her adventurous spirit. They fondly recall the launch of Blanchard's hot air balloon, an event that symbolizes the new attitudes they both embrace. Nathaniel gives Mattie flowers to remember him by as the city shuts its doors to the fever. These memories give Mattie the strength to endure her many hardships, sustaining her hope until the first frost signals the end of the epidemic.

Lucinda, Mattie's mother, acts as the antagonist. Widowed for several years, she has been raising Mattie alone while managing the coffeehouse. Lucinda knows how to endure difficult times and teaches Mattie the same resilience.

Mattie describes her mother as someone who "had given birth . . . in the morning and cooked supper for ten that night." Lucinda is relentless in her efforts. Her tough demeanor forces Mattie to assert herself. Mattie wonders whether her mother finds any joy in life or if it is consumed by bitterness. Lucinda shows little compassion for herself or Mattie, making Mattie's path to adulthood a challenging one.

Lucinda contracts yellow fever. Mattie discovers this when a stranger dumps her mother out of a wheelbarrow in front of the coffeehouse. For the first time, Mattie sees her mother out of control. She fears for her mother's life as she witnesses her shivering and vomiting uncontrollably. Lucinda's eyes are tainted with streaks of yellow and red. Like her mother, Mattie sets aside her fears and sadness to take care of her.

Worried that Mattie might contract the contagious disease, Lucinda sends her out of town to the Ludingtons in Gwynedd with Mattie's grandfather. Mattie experiences a whirlwind of emotions. She wants to nurse her mother back to health but feels powerless against the deadly virus.

Mattie does not learn whether her mother survives the fever. This unresolved tension effectively heightens the novel's suspense.

Mattie's grandfather, Captain William Farnsworth Cook, acts as a protective father figure. He imparts practical wisdom to her, often quizzing her on what a soldier requires for battle. Mattie responds with: a sturdy pair of boots, a full belly, and a good night's sleep.

Mattie and her grandfather set out for the Ludingtons. The coachman grows suspicious of Grandfather's health due to his persistent cough and drowsiness. Fearing he has yellow fever, the coachman abandons Mattie and Grandfather outside Pembroke.

Mattie takes care of her grandfather, making wise decisions to secure shelter, food, and water for them. This experience bolsters her self-confidence and fosters her independence.

Together, Mattie and her grandfather face several adversities. When Mattie falls ill with yellow fever, Grandfather takes her to Philadelphia and helps nurse her back to health. They return to their deserted coffeehouse, but Grandfather dies defending it from thieves who attack in the dead of night.

Mattie mourns his passing and reflects on his life. She insists on a Bible reading during his burial in a mass grave to honor him. Her relationship with her grandfather strengthens her self-reliance and perseverance, teaching her practical ways to handle difficult situations and giving her the courage to face her battles.

After Grandfather's death, Mattie reaches her lowest point. Her familiar life has disintegrated; the coffeehouse is vandalized and empty, and she is surrounded by disease and death. She aimlessly roams the streets, searching for direction.

She discovers baby Nell hiding in a corner, sucking her thumb, with tangled blonde hair and bare, dirty feet. Nell's mother has succumbed to the fever, and Mattie decides to take care of Nell.

Mattie reunites with Eliza, a valued peer of Lucinda who has joined the Free African Society. Deeply involved in the community, Eliza befriends Mattie and invites her to work alongside her as an equal. This opportunity allows Mattie to further recognize her self-worth. Eliza supports Mattie without interference, aiding her growth into the woman she is becoming.

When Nell contracts yellow fever, Mattie and Eliza apply the French medical treatment: fresh air, rest, and fluids. Their approach is successful, and Nell recovers. Nell symbolizes hope for a brighter future, enabling Mattie to embrace the responsibilities of adulthood.

By the novel's end, Mattie undergoes a transformation, realizing the importance of perseverance and recognizing the multitude of choices before her. She nurtures her friendship with Nathaniel, reopens the coffeehouse with Eliza as her partner, and begins to pursue her dreams of a thriving business. Nell remains with her, relying on Mattie as a mother figure.

Lucinda returns from the countryside in poor health. She is forced into a life of leisure and must depend on Mattie to run the coffeehouse. Over time, Lucinda comes to respect Mattie's decisions and treats her with newfound respect and compassion.

Anderson excels at crafting authentic characters and weaving them into realistic themes, all set against a vivid backdrop. She illustrates how this disease transforms her characters, mirroring how traumatic events alter real lives. Young adults will finish this novel feeling hopeful, resilient, and enlightened.