B. 1744
Jamie Colley is the son of a New York dock worker - James Colley. History doesn't record the name of his mother, though the Assassin records note she worked on a plantation in the southern colonies.
As a boy, Colley spent 3 years as a student at the Trinity School, where he was reported to be a bright student, reading everything he could get his hands on - his instructors noted that he was destined for great things. (I know you're wondering: yes, your school's permanent record really is that permanent). However, after that brief period he disappears from the school's attendance rolls - my guess would be he left because he needed to start earning money.
It seems Colley's prospects didn't improve through his teenage years - I have records of him being fined for vagrancy several times, which is never the sign of a high flier. After that, he worked doing odd jobs for various local businesses, finally ending up working for a local physician, where his intelligence was recognized as an asset. He worked for several years as the doctor's assistant, where he met Connor.