The Correspondence series primarily documents Bowman's childhood and young adulthood, from his stay as a boy at a sanitarium in Kansas City for diabetes treatment through his years at Stanford and Princeton. Correspondence between Bowman and his mother, Mary Augusta Brooks Bowman, is particularly rich in part because they wrote each other almost daily and in great detail. Bowman's letters to his mother from Stanford and Princeton, in particular, are lively and quick-witted and reveal his myriad social activities, impressions of college life, and opinions on subjects of all sorts, from family matters to politics to popular films and actors. Correspondence with his father, sister, and brother can be equally revealing but does not match the sheer volume of correspondence between mother and son. Letters from Bowman's friends are also worth noting for their vivid evocations of private school and college life in the 1920s and 1930s. Bowman corresponded with several young women, including a cousin, Edith Brooks, who was traveling in the car with Bowman at the time he was killed. The young women's letters, in particular, contain a vivaciousness and convey their own and Bowman's very active social lives. Bowman also maintained a correspondence over many years with a member of the crew he met on a Cunard Lines voyage he took as a boy with his family. The crew member sent Bowman many letters and postcards from his voyages around the world.

Of particular interest with regard to Bowman's musical career are his letters from Princeton between 1933 and 1936. In between reports on football games and weekend trips, Brooks discussed matters such as Triangle Club work, royalty agreements, and musicians of the day, including Guy Lombardo, who performed his songs "East of the Sun (and West of the Moon)" and "Love and a Dime," as well as his hopes and plans for Hollywood and New York songwriting contracts.

The series includes a letter, from March 1937, in which Brooks details his experiences in Hollywood in his typically spirited manner. The series also contains copies of letters from F. Scott Fitzgerald '17, who wrote to Bowman praising his work on Stags at Bay, and from Cole Porter, who penned a letter of introduction for Bowman to New York theatrical producer Dwight Deere Wiman. This material was collected by Fred Fox and is maintained, along with correspondence between Fox, Bowman's sister Mary, and some of Bowman's Triangle Club colleagues and classmates, in a folder at the end of this series. A copy of the original manuscript of "East of the Sun (and West of the Moon)" and a copy of "You and Romance and Me," a song Bowman wrote with Hoagy Carmichael, are also located in this folder.