Colonel The Honorary In 1845, before retiring to England, he donated the land on which the Church of the Holy Trinity () was built. In 1805, he went to England to study at the Royal Military Academy in Woolwich. He became a Captain in the Royal Engineers and served with them during the Peninsular War, seeing action at the Battle of Barrosa.
He remained with his regiment until 1827, when he was appointed Professor of Fortification at the Royal Military College, Sandhurst.
When he resigned in 1835, he returned to York, Upper Canada, which had been renamed the previous year, to manage his inheritance. He made his home at Elmsley House, which had belonged (though he never lived there) to his father-in-law, and was afterwards lived in by James Bruce, 8th Earl of Elgin.
Macauley became a director of the Bank of Upper Canada. In 1836, he was appointed Surveyor-General for Upper Canada by the new Lieutenant-Governor, Sir Francis Bond Head.
The appointment was disputed because the candidate favoured by the Compact had been ignored and others did not consider Macaulay a genuine resident of the province.
Head advised Macaulay to submit his resignation to the Colonial Secretary, expecting it to be refused, but it was accepted and John Macaulay, no relation, was appointed to the post instead. In 1839, he was elected to the Legislative Council of Upper Canada. Two years later, he was elected to the city council but, again frustrated by the Compact, he resigned after Henry Sherwood was elected mayor instead of him.
In 1845, disgruntled by political life in, Macaulay sold his property there for a profit of £21,000.
Macaulay moved with his family to England. They took up residence at Rede Court, near Rochester, not far from Macaulay"s first cousin, General George William Powlett Bingham C.B., Justice of the Peace, of The Vines, Rochester.
They were the parents of eight surviving children. One son lived in England, another in, another in South Africa and another in New Zealand.