Aaron Sheridan was the lighthouse keeper on South Manitou Island from August 1866 until it ended tragically March 15, 1878. He and his father James, his uncle William and cousins Lyman and Newton Sheridan came from Oswego County in upstate New York to the Traverse City area about 1860. The Civil War called him into the service of his country. In 1863 he was seriously wounded, losing the full use of his left arm. In 1865 he married Julia Moore who was from the Chicago area near where he had been hospitalized and recovered from the war wounds.
Aaron had no previous lighthouse experience but with a determined character and a courageous war record, he was selected for the South Manitou Island keeper job. So he and Julia returned to the area and came to the island. The next twelve years the family was blessed with the birth of six sons. The lighthouse was greatly expanded in 1871, with addition of the tower and a steam powered fog signal. At that time Julia became an official assistant keeper.