Jackson Pollock, shown with one of his paintings in 1952, spent his later years on Long Island.

“Just a few lines to tell you that my seven year old son Manning couldn’t get over your picture Number Nine,” begins a 1949 letter to Jackson Pollock, America’s best-loved abstract impressionist, known for his paint-splattered canvases. “Frankly, it looked like some of his finger painting at school to me. He insisted that I write you to tell you that he cut it out of the ‘Life’ and put it in his scrapbook.”

The note, written by Helen K. Sellers of Charleston, S.C. (and accompanied by a photo of Manning holding his cocker spaniel, Snafu), made it into Pollock’s personal papers. Apparently saved for posterity, the letter now has a much wider audience as part of the “Memories Arrested in Space” exhibit at the Smithsonian’s Archives of American Art (inside the Donald W. Reynolds Center for American Art and Portraiture), a tribute marking the centennial of Pollock’s birth.

“This is not really about looking at his art; it’s about looking at his life,” says Helen A. Harrison, director of the Pollock-Krasner House and Study Center in East Hampton, N.Y., who guest-curated the show. “The mythic side of Pollock is reduced to a very flat portrait. But he was much more well-rounded.”

“Memories” includes photos, letters and other important documents of Pollock’s. Many of the items counter his commonly known persona as a serious, macho Westerner. (In fact, Pollock moved east when he was 18.) One contact sheet of photos shows him holding his pet crow, Caw-Caw; in others, he’s posed casually with family and friends. “I think it might surprise people to know that he smiled,” Harrison says.

Pollock’s career was short: Only 12 years elapsed between his first solo show and his last. He died in 1956 at the age of 44 in a car crash. “Memories” covers his entire life, from his California childhood to his New York City years to his struggles with depression and alcoholism. Examples of his correspondence with art dealers Peggy Guggenheim and Betty Parsons are on display, as is a 1949 issue of Life that contained the first color review of Pollock’s work. “He was such a great story for the media. They could call him Jack the Dripper,” says Mary Savig, an archives specialist at the Smithsonian’s Archives of American Art.

Even after his death, “Pollock was a lightning rod,” Savig says, causing some, like Sellers, to second-guess their definition of art. It looks like her son had the last laugh.

The show takes its name from a few lines Jackson Pollock jotted on the back of a photograph of himself at work, in which he emphasizes that his compositions aren’t accidental. “It’s very poetic for Jackson Pollock,” says Liza Kirwin, acting director of the Smithsonian’s Archives of American Art.

Donald W. Reynolds Center for American Art and Portraiture, 8th and F streets NW; through May 15, free; 202-633-7970, Aaa.si.edu. (Gallery Place)