Nearly seven hours of unreleased interviews with Jacqueline Kennedy, recorded just months after the death of President John F. Kennedy and intended for deposit in a future presidential library, will be released as a book, the publisher Hyperion said on Tuesday. The original interviews with Mrs. Kennedy took place in the spring of 1964 with the historian Arthur M. Schlesinger Jr. as part of an oral history project intended to preserve memories of Kennedy and his administration. In the seven interviews, Hyperion said, Mrs. Kennedy discusses various subjects including her husband’s election campaigns; his handling of challenges like the Cuban missile crisis; her role as a wife, mother and first lady; and what her husband would have done in a second term as president.