Best known for his portrayal of the title character in the "Spider-Man" trilogy, Maguire has also starred in the films "Pleasantville," "The Ice Storm," "Seabiscuit" and "The Cider House Rules."
Variety.com said Maguire is to play Greenberg in "The Crusaders," which is to be directed by Gary Ross and to be written by Danny Strong, based on Greenberg's memoirs, "Crusaders in the Courts."
Maguire will play Greenberg when he was a recent law-school graduate who fought alongside NAACP Legal Defense Fund head -- and future Supreme Court Justice -- Thurgood Marshall to win the 1954 Brown vs. Board of Education Supreme Court case that made segregation in U.S. schools illegal, Variety.com said.
Ross and Maguire previously collaborated on "Pleasantville" and "Seabiscuit."
A former assistant to Ross, Strong wrote the Emmy nominated HBO film, "Recount." He also played the recurring role of Jonathan on the iconic TV series, "Buffy the Vampire Slayer."