The McGill Family papers date from 1885 to 2005 and measure 10 linear inches. The papers are arranged in five series: Eliza and James McGill, Ada McGill Smith, Pearl McGill, Family histories and writings, and Photographs. The bulk of the collection is made up of the correspondence of Pearl McGill, Eliza Cromer Law McGill, and Ada McGill Smith. The letters written to Pearl McGill from her mother and siblings are included in the Pearl McGill series.

The Eliza and James McGill series (1885-1922) includes letters written between Eliza Cromer Law and James McGill prior to their marriage in 1889. The letters discuss arrangements to be made for the care of the Eliza Law's four children from her previous marriage, her opinion on drinking, as well as local news.

The Ada McGill Smith series (1908-1932) correspondence includes letters written home from Marked Tree, Arkansas, between 1910 and 1912 describing the cotton fields, farming practices and living conditions. Other correspondence includes letters written home by Ada Smith during the trips she made to California.

The Pearl McGill series (1902-1924) consists of correspondence, postcards, and newspaper clippings. The correspondence includes the letters Pearl McGill wrote to her family in Grandview, Iowa, between 1911 and 1923. The letters are written from Muscatine, Chicago, St. Louis, Boston, Lawrence, and New York City on a variety of letterheads including the Women's Trade Union League of Chicago, the Button Workers' Protective Union, United Mine Workers of America, and the Hotel Needham in Lawrence, Massachusetts. McGill's letters discuss details of the Muscatine button workers' strike of 1911-1912 as well as the speeches she gave and the money she raised in support of the Muscatine button workers during the lockout and ensuing strike.

The letters encompass a variety of issues including class, socialism, union organizing, and working conditions as well as the day-to-day matters of family life back home in Iowa. The folder titled "Letters from Acquaintances," includes a photocopy of a letter written from Helen Keller to Pearl McGill dated February 19. Although the year is not given it was most likely 1914, a year that Helen Keller is known to have visited Cedar Falls, Iowa. The letter refers to a meeting between the two women at the station in Cedar Falls and Helen Keller offers support and encouragement to Pearl McGill in her efforts to become a teacher.

Several of the postcards depict strike scenes and parades in Muscatine, Iowa, in 1911 and in Lawrence and Lowell, Massachusetts, in 1912. The bulk of the newspaper clippings relate to the death of Pearl McGill in 1924.

The Family histories and writings series (1970-2005) includes booklets and tapes discussing family life, country schools, and farming as well as the booklet Pearl 'And this is why I love the Fight', which was compiled by Pearl McGill's niece, Jean Burns.

The Photographs series (1911-2005) includes a portrait of Pearl McGill which was taken in Boston, Massachusetts in 1911