He lived for a time in South Carolina, after which he returned to England where he successfully practiced as a physician, and in medicine, for a number of years. In 1832, after emigrating to Upper Canada with his family, he settled in Kingston, Ontario. Here, Barker continued in medical practice but developed an interest in journalism, and in 1834 he founded the then semi-weekly British Whig.
The newspaper, now the Kingston Whig-Standard, became the longest continually published newspaper in Canada.