At 11 p.m. on July 1, 1975, Gibson and another attorney went to Marshall's home to ask the justice to intervene on behalf of former Baltimore schools Superintendent Roland Patterson, who was about to be fired. Marshall, in his bathrobe, invited the young men inside. They stayed until 2 a.m.

"I view 'Young Thurgood' as a story about a partnership between two men," says Ron Shapiro, Gibson's law partner and, since 1967, his best friend. "I think that Justice Marshall saw something in Larry that made him think that was a guy he should give some time to.

"It takes people like Thurgood Marshall to change history by changing the law. And it takes people like Larry Gibson to use activism to implement those changes in the streets and homes and lives of African-Americans."

In some ways, the two men couldn't be more different. Marshall never was involved in more than two dozen local, national and international political campaigns, as Gibson has been; and Gibson never wanted to become a judge.

But there also are similarities. For instance, both Marshall and Gibson grew up poor in segregated Baltimore.

Gibson's father was a janitor, while his mother worked as a domestic and cook. The couple had four children and rent money was scarce, so the family moved every 18 months.

"After I finished law school, I was determined to buy my folks a house," he says. "They wanted to stay in the same neighborhood, so I went around and bought the biggest house I could find. They lived there until my father died."

Marshall was a gifted raconteur and so is Gibson. Both men fused idealism with pragmatism and were known for their grueling work ethic. And neither was above being deliberately provocative to make a point.

After helping elect Parris N. Glendening as governor in 1994, Gibson dumped Glendening after they disagreed about funding for Baltimore public schools, and in 1998 campaigned for an opponent, Eileen M. Rehrmann.

Eyebrows also were raised in 1999 when Gibson, a lifelong Democrat, advised and distributed campaign literature for Carl Adair, a candidate in Baltimore's Republican mayoral primary. Gibson describes Adair as a lifelong friend and fraternity brother, and says that he played no formal role in that campaign.

Gibson can be, as Schmoke puts it drolly, "an acquired taste." But the biographer has begun to use Marshall's example to temper his own brash style.

"He could be this persistent, forceful advocate," Gibson says, "but most of his adversaries believed that he had at least heard and understood their views. Sometimes, I think I'm not as persuasive as he was because I'm so intent on advocating my own position."

One of Gibson's favorite stories is of the time that he and some friends participated — or attempted to participate — in a sit-in at a segregated Baltimore restaurant in 1961.

"We went in the front door of the old Oriole Cafeteria," he says.

"I began grabbing food from the counter that I didn't even like, baked fish and this salad with carrots and raisins in it. We were expecting to be thrown out. We didn't expect to eat. But the cashier just rang us up. I had to borrow money to pay for my meal."

He later figured out that the restaurant had received advance notice of the protests and decided to integrate for one day only.

"I still call that salad my Sit-in Salad," Gibson says.

The anecdote is instructive for the pleasure Gibson takes in telling it and for the way in which he gently mocks his 19-year-old self. The strategist in him admires the adroitness with which he and his friends were disarmed. And it's clear that he hates every single thing about segregated restaurants except the people on the other side of the counter.

"At his core, Larry is a guy who wants to build on history and not rest on history," Schmoke says.

"He doesn't want people to read the book and say, 'I'm glad we know want to know what happened in 1928.' He wants people to be inspired by Marshall's story and do better in the future."