The 29-volume collection of DiMaggio's journal -- written from 1982 to 1993 -- offers a glimpse into the life of publicity-shy slugger and will be offered at auction by Steiner Sports, the New York Daily News reported Tuesday.
The sports memorabilia company bought the 2,000-page diary from a group that includes DiMaggio's granddaughters, Paula Hamra and Kathy Stein.
Some entries reflected the time's history, such as his dining with Soviet leader Mikhail Gorbachev and U.S. President Ronald Reagan at the White House. And some showed DiMaggio's desire to protect Marilyn Monroe, to whom he was married for a short time in the 1950s, the Daily News said.
"Book people felt me out with questions pertaining to baseball," DiMaggio wrote on April 28, 1989. "Some part of my private life but not too strong on that. Will not reveal anything in a negative way towards Marilyn -- only books that have come out on her might have not been truthful."
Yankees pitching great Whitey Ford said his former teammate wouldn't want his diary made public.
"I know he was shy," Ford told the Daily News.