Maurice Leyden was born in Collamer, Onondaga County, New York on October 18, 1836, the oldest of the twelve children of Michael and Catherine (Carhart) Leyden. He attended school in Syracuse and the Cazenovia Seminary, then studied dentistry under Dr. Amos Westcott of Syracuse. He enlisted in Company B, 3rd New York Cavalry, on June 13, 1861, and was promoted to 2nd Lieutenant on July 30, 1861; to 1st Lieutenant on June 12, 1863; and to captain on October 10, 1864. He was captured on October 7, 1864 and spent months in Confederate prison camps in Salisbury, North Carolina; Danville, Virginia; and Libby Prison before being paroled on February 22, 1865. After a brief leave he returned to the front. On July 21, 1865 he was transferred to Company C, 1st New York Mounted Rifles, and was breveted major on October 13, 1865, which rank he held at the time of his discharge.

While on furlough in March 1865 Leyden married Margaret "Maggie" Leora Garrigues of Rochester, the daughter of Cyrus and Eliza (Woodruff) Garrigues. The couple had four children: two sons and a daugther (Maud) who died in infancy, and one daughter who survived: Blanche Eloise.

Following the Civil War Leyden settled in Rochester, where he first practiced dentistry with Dr. Frank French as the firm French & Leyden, until he joined George P. Davis as Davis & Leyden in manufacturing dental instruments and amalgams for the wholesale market. Leyden was active in the local and state Republican Party and in local politics, serving a term in the Rochester board of supervisors and as Monroe County Clerk from January 1886 to January 1889. In 1887 he organized the Rochester Title Insurance Company, and held various positions with the firm until his retirement. In 1889 he was elected president of the Rochester Saving & Loan Association. Leyden was also very active in Civil War veterans' associations and reunions, as well as in the Valley Lodge of Masons. He died August 15, 1906.

Margaret "Maggie" Leora Garrigues Leyden was a graduate of the East Avenue Collegiate Institute in Rochester, and an active suffragist. With Susan B. Anthony and other women Maggie Leyden registered to vote in the 1872 elections, and cast ballots. This episode and Anthony's ensuing trial for illegal voting are documented in Maurice Leyden's diaries for the period. Margaret Leyden lived until 1928.

Blanche Eloise Leyden was born in Rochester, New York in 1874. She married Harry C. Andrews in 1931, and died in 1936. Census records indicate that she lived with her parents until their deaths, and no occupation is listed.

Maurice, Margaret, and Blanche Leyden are buried in Mount Hope Cemetery, Rochester, Monroe County, New York.

Margaret Leyden's maternal aunt, Sarah Woodruff Pottle, is also represented in the collection through her diaries. Sarah was the wife of Rochester merchant and farmer Edward L. Pottle. Edward and Sarah Pottle are also bured in Mount Hope Cemetery, Rochester, Monroe County, New York.