Mustered into service as a Private on July 29th, 1861
Died 23 December 1863
Private Lewis was wounded in the right knee joint by a round musket ball at the Battle of Gettysburg on July 1st, 1863. He stayed at the First Corps Field Hospital for two months before eventually being transferred to the Jarvis Hospital in Baltimore Maryland. Gardiner refused to have the leg amputated so the doctors tried to save it with an operation. Private Lewis did not do well after the surgery and would die the following month.
Soon after the war a list was compiled by the 19th Indiana giving the locations of all the burials that were made in National Cemeteries. On this list Private Gardiner Lewis is listed as being buried at the Loudon Park National Cemetery grave number 349. The headstone that is in place for Lewis at this cemetery says "Co. B, 19 MD INF". It should read "19 IN INF".