Montagu, daughter of the second Lord Abercrombie, he took up his residence at Dalguise House, on the banks of the Tay, near Dunkeld.

[3] Fox Maule campaigned during the first election for Perthshire, canvassing in favour of his friend, the Marquis of Breadalbane, then Lord Ormelie.

Having resigned his seat for the Elgin Burghs, he was elected by the city of Perth, which he continued to represent for ten years, until he was called to the House of Lords after his father's death.

In the ministry of Lord Melbourne (1835–1841), Maule was Under-Secretary of State for the Home Department, and under Lord John Russell, he was Secretary at War from July 1846 to January 1852, when for two or three weeks he was President of the Board of Control.

In February 1855, he joined Lord Palmerston's cabinet, filling the new office of Secretary of State for War.

[3] For thirty years he was returned by the Free Presbytery of Dunkeld as their representative elder to the General Assembly, and took an active part in its proceedings.

After the Disruption, when so many proprietors refused sites for the building of churches and manses, it was mainly through his speeches in Parliament that the difficulty was surmounted.

On his death, the barony of Panmure became extinct, but the earldom of Dalhousie (and its subsidiary titles) passed to his cousin, George Ramsay.