The Kate Martinson diary dates from 1872 to 1944 with the bulk of the material dating between 1872 and 1917 and measures 1 linear inch. Almost each year on October 2 from 1872 until 1893 she wrote about the previous year's activities including a recitation of marriages, births, and deaths in her family. She described some of the joys and hardships of life in rural Iowa including a tender account of the brief life and death of an infant child. Her husband George worked away from home for long periods of time, and in 1889 she learned that he had another wife and other children; although she was pregnant, she sent him away and eventully divorced him.

After her marriage in 1897 to Andrew Martinson she resumed writing in her diary, although not with the regularity and depth as previously. Generally it was a report of the comings and goings of their children.

Obituaries of Kate and Andrew Martinson are included.