Claim: Edward Killen, who obtained the rank of Master's Mate in the United States Navy, which is equivalent to the modern rank of Sub-Lieutenant, served the United States of America from 1801 to 1806.
Evidence: Master's Mate United States Navy Master's mates evolved into the modern rank of Sub-Lieutenant in the Royal Navy, while in the merchant service they evolved into the numbered mates or officers. 1801–1806 
Killen joined the Navy on 5 May 1801 as a seaman aboard the schooner Enterprise. After successfully completing this mission in Intrepid, Killen served on board Enterprise until his death on 24 July 1806. Accompanying her to the Mediterranean Edward Killen served with skill and devotion, and was promoted to Master's Mate on 9 November 1803.