What was William Petty Fitzmaurice's term as British Prime Minister notable for?

William Petty, 1st Marquess of Lansdowne, (2 May 1737 – 7 May 1805), known as The Earl of Shelburne between 1761 and 1784, by which title he is generally known to history, was an Irish-born British Whig statesman who was the first Home Secretary in 1782 and then Prime Minister in 1782–83 during the final months of the American War of Independence. He succeeded in securing peace with America and this feat remains his most notable legacy. He was also well known as a collector of antiquities and works of art.

Lord Shelburne was born in Dublin in 1737 and spent his formative years in Ireland. After attending Oxford University he served in the British army during the Seven Years' War taking part in the Raid on Rochefort and the Battle of Minden. As a reward for his conduct at the Battle of Kloster Kampen, Shelburne was appointed an aide-de-camp to George III. He became involved in politics, becoming a member of parliament in 1760. After his father's death in 1761 he inherited his title and was elevated to the House of Lords and took an active role in politics. He served as President of the Board of Trade in the Grenville Ministry but resigned this position after only a few months and began to associate with the opposition leader William Pitt.