Mr John Edward Maguire was born in Boston, Massachusetts on 7 February 1880.

He was the son of John Maguire (b. 1850) and Alice Lilian White (1851-1904). Of Irish descent, both his parents were born in Massachusetts and had been married in Brockton, Massachusetts on 2 July 1879. He had five known siblings: Joseph Francis (b. 1881), Mary A. (b. 1882), Frederick Leo (b. 1885), George Lester (b. 1887) and Elizabeth May (b. 1890).

John was seemingly raised in Brockton, Plymouth, Massachusetts. He appears there on both the 1900 and 1910 census records. He was a salesman for the Dunbar Pattern Company of Brockton. In 1910 he had been in charge of the Brockton Lodge, Elks (a fraternal organisation), and by 1912 he lived at 30 Spruce Street, Brockton. He was unmarried.

He and his friends George Quincy Clifford and Walter Chamberlain Porter left Boston aboard Megantic on 20 February 1912 and they were travelling to Europe for a vacation. After touring England and other parts of Europe Maguire was returning home from his first trip abroad.

All three boarded the Titanic at Southampton as first class passengers. Maguire held ticket number 110469, which cost £26, and he occupied cabin C-108.

Maguire died in the sinking, his body, if recovered, was never identified.

The Worcester Evening Gazette (18 April 1912) reported that upon learning about the death of John Maguire, his unmarried aunt Katherine Maguire (b. 1860), with whom he had a special attachment, took suddenly ill and died from the shock on 16 April 1912.