Task: Question Understanding
Input (English): Passage: The war took a heavy toll, especially in the northern British colonies. The losses of Massachusetts men alone in 1745-46 have been estimated as 8% of that colony's adult male population. According to the Treaty of Aix-la-Chapelle, Louisbourg was returned to France three years later, in exchange for the city of Madras in India, captured by the French from the British. This decision outraged New Englanders, particularly Massachusetts colonists who had contributed the most to the expedition  The British government eventually acknowledged Massachusetts' effort with a payment of £180,000 after the war, which the province used to retire its devalued paper currency. The peace treaty, which restored all colonial borders to their pre-war status, did little to end the lingering enmity between France, Britain, and their respective colonies, nor did it resolve any territorial disputes. Tensions remained in both North America and Europe, and were reignited with the 1754 outbreak of the French and Indian War in North America, which spread to Europe two years later as the Seven Years' War. Between 1749 and 1755 in Acadia and Nova Scotia, the fighting continued in Father Le Loutre's War.
Question: When was Louisbourg returned to France?
Output (English): date