Patrick was the son of small farm holders William and Bridget MacGill of Ardun, Co. Donegal and the eldest of eleven children. He attended Mullanmore National School until he was 10 and at age 12 went to Strabane hiring fair where he was hired by a Co. Tyrone farmer. By age 14 he was working as a “tattie-hawker” in Ayr and outside of potato season he worked as a ‘navvy’ building roads, railways, tunnels and dams. During his time he was a member of many circulating libraries to educate himself and wrote two books (‘Children of Dead End’ and ‘The Rat Pit’) about the harshness of life as a Donegal migratory seasonal worker. Through his character Moleskin Joe he explore the theme of social injustice, “there’s a good time coming, but we’ll never live to see it”. In 1910, when he was working on the Glasgow-Greenock railroad he began selling his poems door to door, so it could be said that Inverclyde is where he really started his literary career. By 1911 he was working as a journalist in London and in 1913 was appointed Kings Librarian to George V.
Patrick volunteered in 1914 at the Chelsea Barracks with the London Irish Rifles. In 1915 he published ‘The Amateur Army’ which was a series of essays recounting the life of a raw recruit and in 1916 published ‘The Red Horizon’ which recorded his first days at the front and ‘The Great Push’ which was written in the trenches and captured the frenzy of attack. He is one of few writers who wrote about the war from the ordinary mans perspective. He was wounded in 1915 at the Battle of Loos when he was shot in his right arm. During his convalescence he married Margaret Gibbons. In 1923 twins Patricia and Christine were born followed by Sheila in 1928. In 1930 they decided to move to Hollywood to further Patricks career as several of his books had been turned into plays and Margaret set up a drama school while they were here.
MacGill spent the rest of his life in America and never returned to Ireland. Ill health lead to him falling silent as an author. Many of his works can be found at archive.org. He is buried at Notre Dame Cemetary, Fall River, Massachusetts.