He was employed as a reporter for The Lynn Item; served on the Mexican border in 1916 with Company A, 9th Massachusetts Infantry; served with Company A, Company A, 101st Infantry Regiment, 26th Division from March 25, 1917, until honorably discharged on March 24, 1919, with nineteen months service in France.
He went on to work as chief purser aboard a United Fruit Company ship (1919–23). From 1923-37, he was secretary (chief administrative assistant) for his brother, Congressman William Patrick Connery, Jr.
Connery was elected as a Democrat to the Seventy-fifth Congress to fill the vacancy caused by the death of his brother, William. He was re-elected to the Seventy-sixth and Seventy-seventh Congresses and served from September 28, 1937 until his death from a heart attack[1] in Arlington, Virginia on October 19, 1941, aged 46. He was interred in St. Mary's Cemetery, Lynn, Massachusetts.