Beverly Gage is a Yale University professor who finds ways to tell us about our present by looking at the past. She is married to a friend of mine, Dan Perkins, who is better known as the cartoonist Tom Tomorrow. 

In her first book, Gage re-examined a somewhat forgotten episode of New York history — a 1920 bombing of Wall Street that had eery echoes for the terrorist attacks that hit the city 81 years later.

Now, she’s working on a book about J. Edgar Hoover, and as she was poring over documents at the National Archives about the former FBI Director, she ran across something of an American history Holy Grail.

It was an uncensored copy of a letter that was sent to the Rev. Dr. Martin Luther King Jr. in November 1964, just as he was about to become the youngest ever recipient of the Nobel Peace Prize.

In her piece about the letter in the New York Times Magazine this morning, Gage explains that since 1961, King had been on a collision course with Hoover, who had started out investigating a former member of the Communist Party in King’s inner circle, which led to an investigation of King himself. King, meanwhile, denounced the FBI’s practices in the South, “accusing Hoover of failing to enforce civil rights law and of indulging the racist practices of Southern policemen.” ...