Mrs Margaret Swift was born as Margaret Welles Barron in Bath, Steuben, New York on 30 September 1865.

She was the daughter of Charles Hazon Barron (b. 1827), a hardware dealer, and Julia A. Welles (b. 1835), natives of New York who had married around 1854. She had four known siblings: Ella (b. 1857), Charles (b. 1859), William (b. 1871) and Bertha (b. 1863). She came from an old English family and could trace her roots back to Ensign Hugh Welles who settled in Wethersfield, Connecticut in 1645.

She first appears on the 1870 census, listed as Minnie and by the 1880 census was living in Milo, Yates, New York and was still attending school. She received Bachelor and Master of Laws degrees from New York University and lectured on law to women's clubs, but never practiced.

She was married around 1899 to Fred Joel Swift (b. 19 March 1862), a realtor originally from Herkimer, New York. The couple remained childless and by 1900 were living in Brooklyn, New York and they later settled in Nyack, New York. She was widowed on 21 October 1907.

Following a tour of Europe Mrs Swift boarded the Titanic at Southampton as a first class passenger (ticket number 17466, which cost £25, 18s, 7d) together with friends, Dr Alice Leader, and Mr and Mrs Frederick Kenyon. She shared cabin D-17 with Dr Leader.

The three ladies were rescued in lifeboat 8. Mr Kenyon went down with the Titanic. Following her arrival in New York aboard Carpathia she stayed with her sister Ella Ford at 3 East Sixty-first Street, she gave an interview to the New York Herald (19 April 1912):

"... as Dr Alice Lieder [sic], my travelling companion, and myself were preparing to retire there came an indescribable wrenching, followed by a fearful recoil. Going out into the corridor I found that, although many passengers had arisen from their berths, comparative quiet prevailed. Several men went to one of the starboard portholes and gathered handfuls of shaven ice and showed them to us without the slightest feeling of alarm. Due to the assurances that we had all received that the Titanic was unsinkable, we felt safe, and after a few moments of inquiry most of those who had gotten up, retired again, with absolutely no thought of the huge vessel sinking. Twenty minutes later, when Dr. Lieder and I were safely tucked away in bed, a steward knocked at our door and informed us that it was the Captain’s orders that we prepare for a possible shipwreck by adjusting life preservers and going to the upper deck so as to be within reach of the lifeboats. This was the first intimation that any one aboard that doomed ship had received that there was a possibility of her going to the bottom, and even then nearly all of us took up the matter lightly enough, many of the women insisting that they would remain on board rather than venture out in the flimsy lifeboats. My companion and myself held back until the first lifeboat had been let down into the water. At that time absolute quiet prevailed. Indeed, at no time did I observe any traces of panic among the passengers. The men kindly helped the women into the lifeboats, many of them laughing and chatting, and few of them dreaming that there was any immediate danger. When the second boat was being filled Captain Smith insisted that we get into it, and as the sailors pulled away from the ship I heard him say, “Row for that light,” and I saw him point to a dim glimmer that must have been three miles distant..."

In years after the disaster Margaret seldom spoke about her experiences but those who did hear her recount her story never forgot her graphic description of the events.

A passionate horticulture enthusiast and a lover of flowers, Mrs Swift twice served as president of the Garden Club of Nyack and for many years was an honorary president. She also helped to organise the Federated Garden Clubs of New York and the National Council of State Garden Clubs, serving as the latter's president from 1933 to 1935. In 1940 she was awarded the medal of the Federated Garden Clubs of New York State. A staunch Republican, she was a member of the Women's Republican Club of Nyack and of the Women's National Republican Club and was an advocate of votes for women. She campaigned for Herbert Hoover in 1932.

She also dabbled in other activities and for thirty-five years was of the Fortnightly Library Club of Brooklyn and she was a former president of the Brooklyn Women's Club. She was one-time president-general of the Colonial Daughters of the Seventeenth Century and a member of the Thursday Class of Nyack and Sorosis, a women's club in New York. She had been prominent also in the State Federation of Women's Clubs and was active in various charities. During WWI she entertained soldiers who were unfamiliar with New York.

Mrs Swift spent her last days living in Nyack, New York close to her sisters Mrs Harry Smith (Ella) Ford and Mrs Barron (Bertha) Berthald. She died at her home, 219 North Broadway, on 29 April 1948 aged 82 and was buried in the Ford Mausoleum in Sleepy Hollow cemetery, Tarrytown, New York, (section Horeb 71, Ford Mausoleum).