On what date did J. Edgar Hoover first go to work for the U.S. Department of Justice ?

If you are looking for the year only , it was 1917.

The year will be fine, the exact date, should anyone be interested was July 26, 1917*.

Thanks for the answer !

* Source material / citations :
- "J. Edgar Hoover : The Man and the Secrets" - Curt Gentry - (Pg. 68)
- "Secrecy and Power : The Life of J. Edgar Hoover" - Richard Gid Powers - (Pg 43)
- "Official and Confidential : The Secret Life of J. Edgar Hoover" - Anthony Summers - (Pg. 28)