Born February 9, 1900, Isabella was the oldest child of wealthy Detroit attorney James Swan and Emma Groh Swan, a descendant of one of Grosse Ile, Michigans early settlers. She and her brother Donald and sister Helen spent their winters in Detroit and their summers on Grosse Ile roaming the 555 acre Groh farm which included the entire southern part of Grosse Ile except for Hickory Island, Elba Island, and the quarry.
The family also owned Snake Island which lay alongside Grosse Ile which they renamed Swan Island, purchasing the old Belle Isle Bridge which they used to connect Grosse Ile to Swan Island. The Swans developed their island with the goal of selling home lots there and accumulated a construction bill amounting to over seven million dollars in 21st century currency.
Most of the lot buyers defaulted on their purchases after the Stock Market crash of 1929, and the Swans couldn’t pay their construction bill. They lost all but 3.5 acres of their island, and plunged into hard times with millions of their fellow Americans. Isabella, 29, resolved to help her family. She had attended Detroit public schools, learning French at Central High School. She went to the University of Michigan, majoring in physics and mathematics, graduating in 1922. In 1923, after recovering from a bout of appendicitis, she accepted a job at the Detroit Public Library, the first in her library career.
In a 1989 Heritage Newspaper Interview, Isabella said that after her family sold their Grosse Ile farm in 1926, they thought they were financially stable, so she resigned from her Detroit Public Library position. Then came the Depression, the Swan Island construction bill, and the farm falling back in their hands with taxes due on it. 
In 1933, the Swan family decided to live on Grosse Ile year around, and Isabella took a job with the Wayne County Library System, managing the small Grosse Ile Library, now known as the 1911 Building owned by the Grosse Ile School District. She recalled that she made 33 cents an hour and “I was mighty glad to get that job. It fed my mother, father, sister, brother, niece and myself. It took some managing.”
In 1937, Isabella transferred to the Trenton Library, then in the city’s municipal building and in 1940, when she was 40 years old, Isabelle enrolled at Columbia University working on a degree in library science. Although she had reservations about going back to school at age 40, her lifelong love of learning motivated her to finish her degree.
During World War II, she worked at the Lincoln Park Library which made gasoline rationing a little easier for her. The Lincoln Park Library had been named the official outlet for wartime and civil defense information and the people in charge of the rationing considered Isabella an essential person. Isabella had a plentiful supply of gasoline.
Isabella’s family took in fliers training at the Grosse Ile Naval Air Base and their families during the World War II and frequently entertained British Royal Air Force pilots training at the base, now the site of the Grosse Ile Airport. Besides working at the Lincoln Park Library, she managed advertising for the Grosse Ile Camera, which her friends Henry and Dorothy Hoch published.
After working at the Lincoln Park Library during the War years, Isabella transferred to the Wayne County Library System’s administrative headquarters in Detroit, serving as assistant county librarian until her retirement in 1961. During her tenure as assistant county librarian, Isabella researched and wrote articles about Grosse Ile and Great Lakes maritime history.
For the first six months after her retirement, Isabella traveled, but then she decided to start researching the first of the books she wrote about Grosse Ile history. Her first book, Lisette, is a biography of Elizabeth Denison Forth, one time slave who prospered enough to invest in steamboats and real estate and left an endowment for building St. James Episcopal Church Chapel in 1867. She published Lisette in 1965.
Continuing in the St. James tradition, Isabella wrote, The Ark of God, published in 1968, for the church’s 100th anniversary. She wrote The Deep Roots, a study of the first 100 years of Grosse Ile history, which took Isabella 14 years to write. According to Isabella, she spent three days a week researching in the Burton Historical Collection at the Detroit Public Library and another three days a week transcribing her notes. She explored museums, libraries, and churches in Windsor and Amherstburg, Ontario and corresponded with researchers in the U.S. and Canadian national archives, the U.S. Library of Congress, and other public and private archives for more information.
The Deep Roots was published in 1976, in time for the bicentennial of the United States and counting from July 6, 1776 when William and Alexander Macomb bought Grosse Ile from the Pottawatomie Indians, the bicentennial of Grosse Ile as well.
In a 1989 interview, Isabella talked about The Deep Roots. “I’ll never regret writing it. I have no regrets for the time I spent on that book. My, I had fun writing that book. A lot of people said I’d never finish it. They were wrong. I guess the ultimate accolade that my book received is that seven copies were stolen from the Trenton Library.”
Isabella Swan died on Friday, November 19, 1993, at her home in her beloved Grosse Ile. In addition to her career as a historian, her accomplishments included founder and life member of the Grosse Ile Historical Society, life member of the Historical Society of Michigan, and member of the National Historical Society and the American Association for State and Local History.
And, documenting the lives of Grosse Ile slaves who would have otherwise been lost to Downriver history.
 Paula Evans Neuman.“Grande Dame” Downriver Historian Isabella Swan is Dead at 93. Heritage Newspapers. News Herald. November 24, 1993. P. 14A