At age 17, Franklin ran away to Philadelphia, Pennsylvania, seeking a new start in a new city. When he first arrived, he worked in several printer shops around town. But, he was not satisfied by the immediate prospects. After a few months, while working in a printing house, Franklin was convinced by Pennsylvania Governor Sir William Keith to go to London, ostensibly to acquire the equipment necessary for establishing another newspaper in Philadelphia. Finding Keith’s promises of backing a newspaper empty, Franklin worked as a typesetter in a printer’s shop in what is now the Church of St Bartholomew-the-Great in the Smithfield area of London. Following this, he returned to Philadelphia in 1726 with the help of Thomas Denham, a merchant who employed Franklin as clerk, shopkeeper, and bookkeeper in his business.
Sources: http://en.wikipedia.org/wiki/Benjamin_Franklin, http://www.ushistory.org/franklin/essays/franklinarrives.htm