The book's protagonist, Jeffery or "Maniac" Magee, is orphaned at a young age and runs away to Two Mills in search of a home. He becomes a legend for his interaction with both blacks and whites as well as his amazing feats such as bunting the frog jokingly pitched to him in a baseball game, untying the huge knot that has long hung in front of a pizza parlor, and running incredibly long distances.
Amanda Beale (and Mrs. Beale, Hester Beale, and Lester Beale)
Amanda Beale is the first person that Jeffery Meets in Two Mills. A resident of East End, the African-American section of the city, Amanda has a passion for reading. Amanda and her family (including her mother and siblings Hester and Lester) attempt to protect Jeffery from the negativity directed at him by other inhabitants of East End and eventually offer him a home.
Mars Bar Thompson
The book's antagonist, at least until the end. Mars Bars Thompson is a big bully who lives in East End and dislikes Jeffery because of his skin color and the fact that he beats him in a race.
John, Piper, and Russell McNab
John is an inhabitant of West End (the white section of Two Mills) who doesn't like Jeffery very much. Piper and Russel are his younger siblings who Jeffery brings back home when he finds them on a quest to escape to Mexico. John welcomes Jeffery into their home because he has brought his siblings back, but Jeffery sees the bad conditions their house and family are in.
A groundskeeper of the local zoo, Earl also takes Jeffery into his home, though it is little more than a shed. Earl has usually lived at the YMCA, but he comes to care for Jeffery on the grounds of the zoo and, in return, Jeffery teaches him to read. Earl was a former minor league baseball pitcher. Earl eventually dies, leaving Jeffery back on his own.
James "Hands" Down
A teen from West End, James is one of the first to know about Maniac's presence in Two Mills when the kid legend intercepts a football meant for him.
A large family from West End who invite Maniac into their home for dinner whenever he's hungry.
Aunt Dot and Uncle Dan
Maniac's aunt and uncle. Aunt Dot and Uncle Dan take Maniac into their house after his parents' deaths but the way they live (buying two of everything so they won't have to speak to one another at all) forces Jeffery to run away.
Maniac Magee Questions and Answers
The Question and Answer section for Maniac Magee is a great
resource to ask questions, find answers, and discuss the novel.
The Lost Year happens after Maniac runs away from his Aunt Dot and Uncle Dan. We really know nothing about what happens during that year up until he shows up in Two Mills. Your speculation would be as good as mine.