One of Billie Holiday's most iconic songs is "Strange Fruit," a haunting protest against the inhumanity of racism. Many people know that the man who wrote the song was inspired by a photograph of a lynching. But they might not realize that he's also tied to another watershed moment in America's history.

The man behind "Strange Fruit" is New York City's Abel Meeropol, and he really has two stories. They both begin at Dewitt Clinton High School, a public high school in the Bronx that has an astonishing number of famous people in its alumni. James Baldwin went there. So did Countee Cullen, Richard Rodgers, Burt Lancaster, Stan Lee, Neil Simon, Richard Avedon and Ralph Lauren.

Meeropol graduated from Dewitt Clinton in 1921; he went on to teach English there for 17 years. He was also a poet and a social activist, says Gerard Pelisson, who wrote a book about the school.

In the late 1930s, Pellison says, Meeropol "was very disturbed at the continuation of racism in America, and seeing a photograph of a lynching sort of put him over the edge."

Meeropol once said the photograph "haunted" him "for days." So he wrote a poem about it, which was then printed in a teachers union publication. An amateur composer, Meeropol also set his words to music. He played it for a New York club owner — who ultimately gave it to Billie Holiday.

When Holiday decided to sing "Strange Fruit," the song reached millions of people. While the lyrics never mention lynching, the metaphor is painfully clear:

Southern trees bear a strange fruit,
Blood on the leaves and blood at the root,
Black body swinging in the Southern breeze,
Strange fruit hanging from the poplar trees.

Pastoral scene of the gallant South,
The bulging eyes and the twisted mouth,
Scent of magnolia sweet and fresh,
And the sudden smell of burning flesh!

Here is a fruit for the crows to pluck,
For the rain to gather, for the wind to suck,
For the sun to rot, for a tree to drop,
Here is a strange and bitter crop.

In 1999, Time magazine named "Strange Fruit" the "song of the century." The Library of Congress put it in the National Recording Registry. It's been recorded dozens of times. Herbie Hancock and Marcus Miller did an instrumental version, with Miller evoking the poem on his mournful bass clarinet.

Miller says he was surprised to learn the song was written by a white Jewish guy from the Bronx. "Strange Fruit," he says, took extraordinary courage both for Meeropol to write and for Holiday to sing.

"The '60s hadn't happened yet," he says. "Things like that weren't talked about. They certainly weren't sung about."

New York lawmakers didn't like "Strange Fruit." In 1940, Meeropol was called to testify before a committee investigating communism in public schools. They wanted to know whether the American Communist Party had paid him to write the song. They had not — but, like many New York teachers in his day, Meeropol was a Communist.

Journalist David Margolick, who wrote Strange Fruit: The Biography of a Song, says, "There are a million reasons to disparage communism now. But American Communism, one point it had in its favor was that it was concerned about civil rights very early."

Meeropol left his teaching job at Dewitt Clinton in 1945. He eventually quit the Communist Party.

And that's where the second part of Meeropol's story begins. The link is the pseudonym he used when writing poetry and music: Lewis Allan.

"Abel Meeropol's pen name 'Lewis Allan' were the names of their children who were stillborn, who never lived," says his son, Robert Meeropol. He and his older brother, Michael, were raised by Abel and his wife, Anne Meeropol, after the boys' parents — Ethel and Julius Rosenberg — were executed for espionage in 1953.