Following his graduation from Harvard, Emmet joined the New York National Guard's69th Infantry Regiment in 1898 as a Second Lieutenant. He remained with the unit when it was federalized for service in the Spanish–American War. Emmet was promoted to First Lieutenant and appointed as the regiment's adjutant. He continued to serve in the National Guard, and remained active in veterans organizations. In 1901, Emmet received his law degree from New York Law School. After attaining admission to the bar in June 1901, he entered his father's law firm, Emmet & Robinson, where he became a partner in 1903. He later practiced in partnership with Langdon Marvin and Franklin Roosevelt at Emmet, Marvin & Roosevelt, a firm first founded by his great-grandfather Thomas Addis Emmet in 1805. Roosevelt, as junior partner, practiced with Emmet at various times in his career, including during Roosevelt's run for vice-president in 1920. Roosevelt left the firm in 1923, which continued to operate as Emmet, Marvin & Martin.
Diplomatic career
After his Roosevelt became president on March 4, 1933, Emmet was rumored to be considered for various diplomatic posts, including U.S. Ambassador to Italy, then Minister to Portugal or Hungary, which he reportedly declined, and then as "Ambassador to Germany or Minister to Austria because of his familiarity with Central European politics." On December 27, 1933, Roosevelt named Emmet, a fellow Democrat, as the U.S. Minister to the Netherlands. Emmet did not serve under this appointment however as he was commissioned during a recess of the U.S. Senate, and was reappointed by Roosevelt on January 15, 1934 to succeed Laurits S. Swenson. He presented his credentials on March 21, 1934 and served as U.S. Minister until he left his post on August 21, 1937. Following U.S. Minister George S. Messersmith's appointment as Assistant Secretary of Stateunder SecretaryCordell Hull in 1937, Roosevelt nominated Emmet to succeed Messersmith as the U.S. Minister to Austria on July 13, 1937. Emmet, who was ill with pneumonia when he arrived in Austria, presented his credentials to PresidentWilhelm Miklas in Vienna on September 14, 1937 but only served less than two weeks in this role until his death on September 26, 1937.
Personal life
On September 18, 1905, Emmet was married to Pauline Annie Ferguson, the daughter of New York born Paul Dudley Ferguson, the co-founder and treasurer of Gordon & Ferguson from St. Paul, Minnesota. Together, they lived at 39 East 63rd Street and, later, 3 East 94th Street in Manhattan, and between November 1913 and October 1919, owned Bonito, a mansion and estate overlooking the Atlantic Ocean located at 466 Gin Lane in Southampton, New York. Pauline and Grenville were the parents of:
Pauline Temple Emmet, who died unmarried.
Grenville Temple Emmet Jr., who married Anne Livingston Eustis, daughter of William Corcoran Eustis, in 1937. He later married Elizabeth Chace in 1973.
