Mary Amelia Grant's family papers contain correspondence, diaries, legal documents, published and unpublished writings, clippings, and photographs regarding her Grant and Bradbury family members. The collection consists primarily of 19th and early 20th century correspondence and legal documents. The latter trace the English roots of the Bradbury family and the ties of its members from England to America. The correspondence includes 19th century correspondence between Bradbury family members living in Saddleworth, England and Ashton-under-Lyne, England with those living in the United States, letters from the siblings of Dr. Grant's grandmother (Mary Brown Bradbury) who resided on the Isle of Man, Dr. Grant's transcriptions and summaries of her grandfather William H. Bradbury's Civil War letters, and her transcriptions of letters written by her cousin Gilbert Venable Bradbury while serving in World War I. Many of the letters to Dr. Grant's parents of Topeka, Kansas are to her mother, Jennie Bradbury Grant, written chiefly from her mother's Bradbury parents, brothers, and uncles. Included in Dr. Grant's personal correspondence are her letters to her parents while studying in Italy in academic year 1919/1920, as well as her incoming letters in succeeding decades from Marco Peyrot, an Italian professor with whom she studied in Italy.

The collection's family diaries include many kept by Dr. Grant's father and mother, dating from 1870 to 1931, and original diaries or transcripts of diaries kept from 1860 to 1896 by Dr. Grant's grandfather, Elisha Grant. Included are manuscripts of the writings of William H. Bradbury and of Dr. Grant's aunt Kate Bradbury Griffith. In Box 13 Folder 12 are needlepointed medallions that contain locks of hair and photographs of William H. and Mary Bradbury. With few exceptions, each document in the collection is accompanied by Mary Amelia Grant's separate handwritten transcription, occasionally with added commentary or explanation. Her transcriptions are in English for letters received in Italian. An audio cassette of Mary Grant's funeral service is in Box 13. Oversize documents and newspapers are at RH MS R197 and RH MS R199.

The collection's photographs (at RH MS-P 695) contain daguerrotypes, ambrotypes, and tintypes as well as prints. Included are images of the Bradbury family residences in England, Illinois, and Topeka, as well as formal portraits and candid photographs of various family members. A majority of the prints are of Dr. Grant's uncle Elwood S. Bradbury of Kansas City, his wife Ada Venable Bradbury, and their children.