WASHINGTON — The new movie “Marshall” shows a Thurgood Marshall that most people don’t know: a young brash NAACP lawyer used to working alone instead of the Supreme Court justice he would become.

Portraying that Marshall was challenging for Chadwick Boseman, who already portrayed icons like Jackie Robinson and James Brown.

In the new movie “Marshall,” Boseman as Marshall grows from a loner to leader to help solve a Connecticut case in which a black chauffeur is accused of attacking a white socialite.

Boseman told The Associated Press he read books on Marshall and pored through his early cases.

But the South Carolina native said growing up in the South made it easier to channel Marshall’s frustration at the racism he faced as an NAACP lawyer at the beginning of his career.