He was first employed by a copperplate-printer in Philadelphia, but quitted this occupation for the loom, at which he worked about a year in Philadelphia, and at Shepherdstown, in Virginia. In 1795, he traversed a large portion of the State of New Jersey as a pedlar, keeping a journal,--a practice which he had followed during his wandering life in Scotland. He now adopted the profession of a schoolmaster, and was successively employed in this vocation at Frankford, in Pennsylvania, at Milestown, and at Bloomfield, in New Jersey. In preparing himself for the instruction of others, he essentially extended his own acquaintance with classical learning, and mathematical science; and by occasional employment as a land-surveyor, he somewhat improved his finances. In 1801, he accepted the appointment of teacher in a seminary in Kingsessing, on the river Schuylkill, about four miles from Philadelphia,--a situation which, though attended with limited emolument, proved the first step in his path to eminence. He was within a short distance of the residence of William Bartram, the great American naturalist, with whom he became intimately acquainted; he also formed the friendship of Alexander Lawson, an emigrant engraver, who initiated him in the art of etching, colouring, and engraving. Discovering an aptitude in the accurate delineation of birds, he was led to the study of ornithology; with which he became so much interested, that he projected a work descriptive, with drawings, of all the birds of the Middle States, and even of the Union. About this period he became a contributor to the "Literary Magazine," conducted by Mr Brockden Brown, and to Denny's "Portfolio."