J Edgar Hoover had risen to the top of what would become the FBI by age 24; what had he done to distinguish himself by that time? Was this as extraordinary a meteoric rise as it sounds?

There's still plenty to be said about this topic, but while you're waiting for fresh answers you might like to know that a fairly similar question came up here a few months ago. While you're waiting you might like to review that thread:

It took J Edgar Hoover just two years to go from a legal clerkship to a division head. What did he do his first two years of law enforcement to stand out?