He was born in County Wexford, Ireland in 1803, the son of Hunter Gowan, an Orangeman and small landowner and godson of George Ogle, a grand master of the Irish Orange Order.

Hunter Gowan led a yeomanry corps known as the "Black Mob" which was accused of committing atrocities against Catholic civilians before and after the outbreak of the Wexford Rebellion; he remains a hate-figure in local nationalist tradition.

Gowan was elected to the Legislative Assembly of Upper Canada for Leeds in 1834 and 1835 but was unseated due to violence at the polls by his Orange supporters.

During the Lower Canada Rebellion of 1837, he helped raise a company of volunteers which also fought at the Battle of the Windmill.

After the rebellion, Gowan declared his support for responsible government and the division of the clergy reserves among all recognized religious groups in the province.