Folger served as a lighthouse inspector before becoming commander of the Philippine Squadron during the Philippine–American War, and was briefly Commander-in-Chief of the United States Asiatic Fleet.

He entered the United States Naval Academy, which moved from Annapolis, Maryland, to Newport, Rhode Island,[i] for the duration of the war, as a member of the class of 1865.

He then served on the training ship USS Sabine,[ii] where he remained through the end of the war in April 1865 and until 25 July 1865.

After leaving Hartford, he had duty at the Norfolk Navy Yard in Portsmouth, Virginia, for a time in 1868 before reporting aboard the screw frigate USS Franklin, the flagship of the European Squadron, in October 1868.

[3][4] Folger returned to sea as the commanding officer of the screw corvette USS Quinnebaug in the European Squadron.

[3][4][6][7] Folger became commander of the Philippine Squadron of the United States Asiatic Fleet in early 1904[8] and was soon promoted to rear admiral, on 1 June 1904.

Folger House, his home of many years in Cornish, New Hampshire, is on the National Register of Historic Places in the United States.