The majority of the Grace (Pettingill) Hogan van Steenwyk series consists of a correspondence file that dates from 1922-1972. The letters are almost entirely personal. The bulk of the correspondence dates from 1922-1925, and consists of letters from her first husband, James C. Hogan. Included with them are letters and segments of letters by Grace in response which may have been drafts of her letters.

Other materials relating to Grace van Steenwyk include two account books dating from June-November 1916, and from 1949-1951; an undated address book, and two brief diaries, one dated 1918 and the other kept from Jan. 1-Feb. 10, 1923. Also available are Pettingill Family records (1802-1947) that were photocopied from the family Bible.