The bulk of the collection is composed of letters Carpenter received and duplicates of many of those that he sent. Many of them are of an essentially personal nature. In later life he became particularly interested in family genealogy and many letters were written and received on this subject.

Included in the collection are a number of writings by Carpenter relating his experiences as a lawyer and judge. References to Michigan Agricultural College (now Michigan State University) appear throughout the collection as Carpenter had two brothers and two sisters who also attended M.A.C.

There are letters from Europe written during World War I by his son, Rolla, and a diary kept by his son-in-law, Dr. Frederick Buesser (1881-1950). This diary is valuable for its day-to-day accounts of life in the medical corps. The diary includes a good description of Armistice Day in 1918.

Carpenter's correspondence includes letters from several prominent people including Woodbridge Ferris, Charles Evans Hughes, John Bassett Moore, Elihu Root, and William Howard Taft.