When I was a junior in college, I had to do a project that involved interviewing a journalist you admired. I wrote to Jack Newfield. He never responded.

Five years later, when I was a reporter at the Newark Star-Ledger covering corruption and organized crime, a friend suggested I have lunch with Jack to talk about doing a freelance piece for the Village Voice on a then-secret probe that became known as ABSCAM. He was cordial, but he was way ahead of me on the story and didn’t need my help.

The third time I came in contact with Jack, I was a rewrite-man at the Daily News and he’d just been hired there as a columnist. I expected the worst. Instead, I got the best. Over the past 18 years, Jack Newfield became my mentor, my champion, and, most important, my friend.

We worked together as reporters, most memorably on a huge profile of Mike Tyson just as the fighter’s life began imploding some 15 years ago. For most of the past 13 years, I was Jack’s editor. He was an excellent reporter, a wonderful writer, and the world’s worst speller. We went on strike together at the Daily News, got fired together at the New York Post, and worked side by side as columnists at The New York Sun until the end came yesterday at Columbia-Presbyterian Medical Center after his short, fierce battle with cancer.

He was generous with his advice and his time, and he was always eager to work with – and teach – any young reporter I asked him to mentor.

It was never enough for Jack simply to serve as mentor. He had to get involved in the reporter’s life, in the most positive ways. He always insisted on taking the reporter for long working lunches, assigning tons of research so the reporter would really understand the project, and helping his student learn the craft.

Jack made his name as an investigative reporter at the Voice, when it was more about journalism and less about sexual orientation. He exposed greedy nursing-home operators, mob-tied contractors, and corrupt politicians. He was famous for his carefully crafted annual reports about the 10 worst judges in the city, or the 10 worst landlords.

But his writing also sang the song of New York; of its history, of its fabric, of the poor and helpless who live in the shadows at the financial capital of the world.

He wrote about the dangers of lead paint to children, until lawmakers started acting on it. He wrote about nursing-home parasites, until they were indicted. He wrote about companies that exploited workers, about corrupt boxing promoters who traded on fighters and then discarded them when they had lost their skills.

And he wrote about his love of New York and the honest politicians, labor leaders, and just plain folks who make it the best city in the world.

He was born in “Do-or-Die Bed-Stuy.” He went to Boys High before it was burdened with the name Boys and Girls High School. He married a New Yorker, Janie Eisenberg, and they raised their children, Rebecca and Joey, in Greenwich Village.

He found his heroes in Jackie Robinson, Pee Wee Reese, I.F. Stone, Jimmy Cannon, Ray Charles, Dr. Martin Luther King, and Robert F. Kennedy.

He took part in civil-rights marches in the South in the early 1960s, and he wrote award-winning books, like “City for Sale,” exposes, like “Only in America: The Life and Crimes of Don King,” and a stirring memoir called “Somebody’s Gotta Tell It,” in which he did just that.

After Bobby Kennedy was assassinated, Jack said he’d never get close to another politician. But, afflicted with what he called “Losing Side Consciousness,” he continued to fight for the little guy and champion the men and women who fought on the side of the angels in every arena, from politics to education, from labor unions to boxing.

He was involved in making documentaries about RFK, trail-blazing boxer Jack Johnson, and the 1962 bout in which Emile Griffith pummeled Benny Paret to death, and he helped get at least one innocent man out of prison.

He had an amazing collection of friends in all walks of life. They included Teddy Atlas, Jose Torres, and scores of others in boxing; Mario Cuomo and Freddy Ferrer in politics; honest labor leaders like Danny Kane and Dennis Rivera; lawyers like Tom Puccio; judges like Ed Korman and Milton Mollen; writers like Wayne Barrett, Pete Hamill, Mark Jacobson, and Jimmy Breslin; singers like Lloyd Price, and at least one legendary gangster. The list goes on forever.

He mentored future reporting and writing greats like Maggie Haberman, Devlin Barrett, and Geoffrey Gray, and he always encouraged them to report honestly, write the truth, and strive to do well and do good. His name, reputation, and legacy will live on in his books, articles, friends, and family. We all will miss him, but our lives have been richer simply for having known him.