How Old Was Elvis Presley When His Father Was Jailed For Forgery?

Elvis Aaron Presley was born in January 1935 and his father, Vernon Presley, was jailed for forgery in 1938, so he was three.
Vernon Presley was jailed for three years although he only served eight months.  He had, along with his brother in law (the brother of Elvis's mother) and another man called Travis Smith, altered the amount on a cheque from $3 to $8.  The cheque had been made out by Orville Bean, who was Vernon's boss at the time.
Whilst this amount may seem incredibly small now, three dollars was worth a lot of money in 1938.  But it was quite a tough sentence, since he was sent to the Mississippi State Penitentiary.  
Whilst Vernon was in prison, Gladys (Elvis's mother) could not cope financially and she and Elvis were made homeless when she lost their house.  They had to move in with Vernon's relatives, in order to survive.  Throughout Elvis's childhood they lived in poverty  which is thought to have had quite an impact on him in later life.