CONCORD, N.H. — CONCORD, N.H. — Among the 1.5 million condolence letters sent to President John F. Kennedy’s widow after his assassination in 1963 were more than two dozen from Jane Dryden, a dogged and dramatic 11-year-old who churned out a letter a week for six months straight.

“I know that you hate the whole state of Texas. I do to,” she wrote to Jacqueline Kennedy from Austin in January 1964. “I wish I lived in Washington, D.C. where maybe I could maybe see you standing on your porch. I am determined to move there as soon as I can. I would feel safer there.”

Given the overwhelming volume of mail — 800,000 letters in the first seven weeks alone — most of the condolence letters were destroyed. But at least one of Dryden’s notes ended up among the 200,000 pages that were sent to the John F. Kennedy Library in Boston, where they sat largely ignored until historian Ellen Fitzpatrick decided to write “Letters to Jackie: Condolences From a Grieving Nation.”

The book, released last week by HarperCollins, includes more than 200 never-before published letters divided into three categories: vivid recollections of the day Kennedy was killed; letters that express views on society, politics and the presidency; and personal experiences of grief and loss.

Larry Toomey of Upper Darby, Pa., didn’t even wait until Kennedy’s death was announced before starting his letter.

“My dear Mrs. Kennedy, Even as I write this letter, my hand, my body is trembling at the terrible incident of this afternoon. I am watching the CBS-TV news report. No official word as yet.”

Writing two days later, eighth-grader Mary South described learning that the president had been shot just as she sat down to play the church organ at her Catholic school in Santa Clara, Calif.

“I tried to tell myself he would be all right but somehow I knew he wouldn’t. ... the tears wouldn’t stop. The slightly damp keys were hard to play but I offered it up that the President might live,” she wrote.

In return for her letter, she received a small card printed with the words “Mrs. Kennedy is deeply appreciative of your sympathy and grateful for your thoughtfulness.”

“Getting that back felt like: She saw this. Jackie saw this,” South, whose married name is Mary Certa, said in an interview Thursday. “I felt good that I had done something. I just wanted her to know how upset we were and how helpless we felt.”

When one of Fitzpatrick’s researchers called and read her letter, “I started to cry all over again,” said Certa, 60, of Campbell, Calif. “It was like I was right back there in 1963.”

Fitzpatrick was at the Kennedy library researching a different book when she asked to see some of the condolence letters in hopes of getting a sense of how Kennedy was perceived by Americans in his own time. As soon as she started reading, she was hooked.

“It was like the roof came off the building, the walls dropped away, the floor came out from under me. I was absolutely floored by what I’d begun to read,” she said Friday. “I have been teaching American history for 30 years, and I’m not sure I’ve ever seen a collection as powerful and that represented so many ordinary people speaking from the heart about their views about American society, and politics, and the president.”

Fitzpatrick, a University of New Hampshire professor, soon discovered why the letters had never been published: she would have to get permission from each writer before including it in the book. But after she whittled down her list of favorites from 3,000 to 240, only five of the 220 or so she was able to track down declined to be included.

“There have been so many books about the Kennedy assassination. We’ve heard from the experts, we’ve heard from the conspiracy theorists, we’ve heard from people in the Kennedy administration, but here are the voices of those voiceless, everyday Americans,” said Fitzpatrick, who said she was surprised at the eloquence of the writers, no matter how uneducated or young.

“I’m just an average American — average mentality, average housewife, average housing, average size family, a year younger than you and perhaps a little more sensitive than some, but I will always have a warm spot in my heart for both of you as long as I live,” wrote Marilyn Davenport of New York, who included her phone number “if you ever want to talk.”

Barbara Rimer was 15 when she wrote “I promise you that I will give body and soul to perpetuate the very ideals President Kennedy lived for.”

Rimer, now dean of the University of North Carolina’s Gillings School of Global Public Health, didn’t even remember writing to Mrs. Kennedy until contacted by Fitzpatrick.

“When I read it, I thought, ’Wow, was I naive!’ I don’t know how many people write letters to the president today or to Michelle (Obama), but it seemed incredibly naive,” she said.

But Rimer also realized that she has kept her promise to Mrs. Kennedy through her career in public health and by encouraging students to give back at the local, national and global level.

“When I saw this letter, it made me realize how long I’ve been on a path I really wasn’t aware I was on, so I’m really grateful to the author of this book for kind of giving me back a piece of my history,” she said.

For Jane Dryden Louis, author of the weekly letters, the assassination coincided with her growing awareness of the world outside her neighborhood. She remembers being drawn to the drama and pageantry of the Kennedys, and the tragedy as well. After the assassination, she set up an altar with candles in her bedroom, and she and her friends pretended to be Jacqueline, Teddy and Bobby Kennedy.

“They say I look like you, too, although I am blonde and wear glasses,” she wrote to Mrs. Kennedy.

As an adult, Dryden Louis, who still lives in Austin, has worked as pastoral minister, helping families prepare for a loved one’s death.

“I can almost still recognize a piece of myself that’s drawn to be in relationships with people in that sort of deep and tragic but very rich context,” she said. “It’s still me.”

One of the shortest letters came from Martin Rosenberg, a student at the University of Massachusetts who wrote: “Dear Mrs. Kennedy: I have never seen our football players cry ... but today, they did.”