Those are indeed my ancestors. James Albert Alger and his son, James Albert Alger, Jr (my grandfather) both attained the rank of Rear Admiral, USCG. (The senior JAmes Albert was in the sea rescue service prior to its being absorbed by the USCG..hence the designation after his rank that you found) My Uncle David attained the rank of Captain, USCG. Their sister, Julie Hill Alger was a well-known poet and scholar.
I've emailed you and look forward to receiving any additional information and links you have found.