James M. Ambler was a Confederate cavalryman during the American Civil War (1861–1865) and, after the war, a United States Navy surgeon. Ambler graduated from medical school in Baltimore, Maryland, in 1870 and joined the Navy, serving on various ships and at the Norfolk Naval Hospital. In 1878, he reluctantly volunteered for service with an Arctic expedition aboard the Jeannette, a ship commanded by George W. De Long. The ship became imprisoned by ice late in 1879, and Ambler did well to keep the crew not only alive but relatively healthy. Still adrift in June 1881, the Jeannette struck ice, which crushed its wooden hull. While a few of the crew’s thirty-three men survived, many froze to death, drowned, or starved, including Ambler, who died with De Long sometime around October 30, 1881.