On page three of “Five Presidents” Clint Hill writes:
“On September 22,1958, I was given a badge, handcuffs, holster, gun, and ammunition, and officially sworn in as a Special Agent in the United States Secret Service. I was taken out to the shooting range at the U.S. Mint in Denver to make sure I could qualify, and that was it. There was no other immediate training, except for reading the Special Agent Manual.”
Clint Hill, with Lisa McCubbin, has written three books. “Mrs. Kennedy and Me”, “Five Days in November”, and “Five Presidents”. They are all very well written and highly recommended, especially if you are interested in what the Secret Service does and what the people that Clint Hill protected were like.
Everything that I have read suggests that their mission is all about protecting the people who they are assigned to protect. I believe that in 1963, that was the President, the Vice President, and their families.