Lt. Drake is an agent with the U.S. Naval Intelligence.
His rank is mentioned above instead of a first name because despite having 25 short adventures told over the course of two years, no first name is ever given. He is referred to as Lieutenant sometimes and as Drake others but never anything else.
His given name is not the only thing left unsaid. His entire history is a clean slate. Where he is from, how and why he joined the Navy, what he did to become a lieutenant and how long did it take are all mysteries, as is how he came to be in the Intelligence field.
Very little is, in fact, known about Drake.
He is male. He is likely in his late 20's or early 30's based on his depiction although he might be younger if one went by his far too often rashness.
Drake is quite good looking with blond hair frequently shown to be slightly wavy. He is athletic and remarkably agile, which is good because people are constantly throwing things at him or shooting at him or leaving bombs in his vicinity. He sports usually a pencil-thin mustache which adds to his dashing, almost swashbuckling image.
As mentioned, Drake is an intelligence agent. He serves during the years leading up to America's entry into the Second World War with his last recorded adventure taking place four months before the attack on Pearl Harbor. Exactly how long he has been with that branch is not known but it must have been at least a couple of years because his reputation is already established.
He obviously likes to work alone because he never has anyone assigned with him and some of the missions are rather dangerous from the outset. It could also be that no one else would work with him because he tends to break through doors not knowing what is behind them and more than once ending up unconscious and ready to be dispatched.
Drake has no apparent long-term love interest as he definitely has an eye for the young ladies he meets in his work and is not the least bit shy about asking for a date with them when the job is done. He must have a way with them because one woman risks her own life to save his. (This woman is the mysterious Miss X, a masked vigilante out to stop enemy agents on her own. She comes and goes in a few issues towards the end of Drake's recorded escapades and was actually more interesting and capable than Drake.)