Duncan Little was originally from Ireland, the youngest son of a large family, which is confusing, seeing as they were the Little family. He entered the priesthood at a young age, and was sent to Africa as a missionary in 1756.
Little spent several years in Africa, but in 1760 he returned to Ireland, leaving the priesthood entirely - I'd tell you why, but it seems that information is locked behind a wall at the Vatican and I'm not hacking into their records today as they seem to have changed their password from W3LOV3POP3 again. The next information I have about him is as a passenger on a ship to Boston in 1763. From his letters, it seems his family more or less drove him away over his split with the Catholic Church. (Blood being thicker than water and all of that.)
Little settled in Boston's North End, where he gained a reputation as a good mediator - fair and less expensive than going before the local judiciary. When he wasn't spending time at the local pub, he was helping people to solve their problems - generally by talking them down from a fight, which seems to be all that really happened in Boston in those days. And by those days, I mean anything up to the present day. Little was the first person people called when there was a scuffle, and his usual table at the King's Horse tavern was known locally as "Little's Court" - a moniker the British cracked down on in 1770. Because we like to ruin everyone's fun.