Lewis Heermann, born in Kassel, Germany, 3 August 1779 was commissioned Surgeon's Mate in the United States Navy 8 February 1802. On 16 February 1804, during the War with the Barbary States, Lieutenant Stephen Decatur left Heermann in command of the bomb ketch Intrepid while he and a fearless band of American seamen boarded the captured frigate Philadelphia in Tripoli Harbor, swept her Barbary captors' crew overboard, and set the frigate ablaze.
When hostilities with the Barbary States closed in 1805, Heermann returned to the United States but soon took leave of absence to study in Europe until 1808 when he returned to active duty in Norfolk, Virginia. Largely due to his pleas for better medical care for the men of the Navy, Congress passed a bill authorizing the construction of hospitals at several naval stations, but the first official U.S. Naval Hospitals were not actually built until after Dr. Heermann's death.
He was transferred to New Orleans, Louisiana in August 1811; and, with the exception of a year in the North for his health and an assignment in 1830 in the Mediterranean where he served for an unknown time as Fleet Surgeon of the Mediterranean Squadron, he remained there until he died in May 1833.