The date of his arrival at Quebec is not known but, in 1791, he was involved in administering the dissolving of a partnership between Alexander Davison and John Lees.
Monro later became partners with Mathew Bell and, with George Davison, they purchased the Saint-Maurice ironworks in 1793.
George Davison died in 1799, which left Monro and Bell the sole owners of the ironworks at Saint-Maurice.
In 1804, he was elected to the Legislative Assembly of Lower Canada for Saint-Maurice and generally supported the English party.
(Levett later hyphenated his last name to Levett-Prinsep, and inherited Croxall Hall, Derbyshire,[1] a holding of his uncle Thomas Prinsep's family.