Beans is a ten-year-old boy born and raised in Key West during the Great Depression. He acts as the resourceful leader of his neighborhood marble gang, the Keepsies. Constantly observing the dishonesty of the adults around him, he decides that playing by the rules will not help his impoverished family survive.

Kermit is Beans's eight-year-old brother and constant companion during the summer days. He is talkative, generally pleasant, and prone to taking adults at their word. His physical vulnerability to illnesses like intestinal worms and fevers keeps him frequently bedridden.

Johnny Cakes is a local boatman known throughout Key West as a criminal who skirts the law. Sporting a white linen suit and a Panama hat, he runs untaxed liquor from Cuba and uses his smooth charm to recruit children into helping him bypass authorities.

Mr. Stone is a federal "New Dealer" dispatched by President Roosevelt to salvage Key West's ruined economy. He envisions transforming the dilapidated, garbage-filled streets into a pristine tourist destination, though he initially struggles to understand the local climate and customs.

Dot is a sharp, confident girl around Beans's age who stands out as the best female marble player on the island. She repeatedly challenges the all-boy Keepsies gang to matches and engages in an escalating prank war with Beans over a shipment of Cuban pineapples.

Murry is a quiet, mysterious man who watches movies in the dark and leaves behind a glass-topped walking stick. Living with leprosy, he restricts his movements to nighttime hours to avoid being sent to a quarantined colony.

Ma is the hardworking matriarch of the Curry family. With her husband out of work, she hand-washes laundry for neighbors using harsh detergents that leave her hands raw and aching. She takes great pride in her sewing skills.

Poppy is Beans's father, a man heavily impacted by the economic shutdown of the Great Depression. Unable to find local work, he makes plans to travel to New Jersey to find a job, putting immense stress on the household.

Buddy is the three-year-old youngest child of the Curry family. He frequently sleeps in a wagon pulled by his older brothers or stays confined to his crib with an old girdle.

Pork Chop is Beans's best friend and a core member of the Keepsies gang. He lives in a busy, lively house that serves as a neighborhood hub due to his mother's cooking and the telephone they allow others to borrow.

Nana Philly is Beans's notoriously mean grandmother. She lives in a large home filled with silver and oil paintings from her late wrecker husband's salvaging days, looking down on the Curry family due to a long-standing grudge.

Termite is a scruffy stray dog who unilaterally decides that Beans is his owner. He follows the boy everywhere, barking at strangers and attempting to intervene when Beans engages in questionable activities.

Also known as Marvin, Too Bad is an eager neighborhood boy desperate to join the Keepsies marble team. His family holds one of the official keys to the town's fire alarm boxes.

Winky is a slick-haired local adult who resells used, rinsed cans to a Cuban restaurant. He habitually cheats the neighborhood children out of their promised wages.

Ira is a dependable boy in the neighborhood and a core member of the Keepsies marble gang alongside Beans and Pork Chop.

Pork Chop's mother runs a lively household, cooking delicious fritters and selling tickets for the local Cuban lottery, bolita.

A beautiful local woman who reminds Beans of a movie star. She struggles to comfort her fussy infant son until Beans offers a homemade remedy.

Mrs. Albury's infant son whose severe diaper rash makes him incredibly fussy until Beans cures it with a cornstarch mixture.

The theater ticket seller, named for his habit of demanding his tools back from borrowers. He dismisses Beans's questions about the mysterious man in the balcony.

An unpaid firefighter at Station No. 3 whose laundry Ma washes for free. He works tirelessly despite the lack of a salary.

A cousin in the extended family who steps in to help care for Nana Philly when she requires full-time assistance.