British North America Act of 1867 at the castle alongside the first Prime Minister of Canada John A. Macdonald, George-Étienne Cartier and Alexander Tilloch Galt, who signed the visitor book in 1866. The 4th Earl presented the Act to Parliament in February 1867 and this led to the foundation of the present-day nation of Canada later that year. After the discovery of documents between him and John A. Macdonald, showing eight weeks of nearly daily correspondence, Janice Charette, the Canadian High Commissioner to the United Kingdom, recognised the central role of the 4th Earl in the creation of Canada by planting a maple tree on the lawn on 11 January 2018. 20th century At the beginning of World War I, a hospital for war wounded was opened at Highclere Castle, with Lady Carnarvon helping with the organisation and assisting as a nurse. The castle became home to Egyptian artefacts after the 5th Earl, an enthusiastic amateur Egyptologist, sponsored the excavation of nobles' tombs in Deir el-Bahari (Thebes) in 1907, and employed archaeologist Howard Carter in the search for the tomb of Tutankhamun. During World War II the castle provided a home for dozens of evacuee children. The estate was the location of several crashes of allied aircraft, including a B-17 Flying Fortress, parts of which are now in the possession of Highclere. 21st century In the 21st century Lord and Lady Carnarvon undertook repairs to the roof. In 2007, they created the Egyptian Exhibition, which lies in the cellars of the castle and tells the story of the discovery of Tutankhamun's tomb by the 5th Earl. By 2009, the castle was again in need of major repairs, with only the ground and first floors remaining usable. Water damage had caused stonework to crumble and ceilings to collapse; at least 50 rooms were uninhabitable. The 8th Earl and his family were living in a "modest cottage in the grounds"; he said a lack of repair by his ancestors caused the castle's long-term problems. Repairs needed for the entire estate were estimated to cost around £12 million, £1.8 million of which was urgently needed just for the castle. The castle was used as the main filming location for the ITV/PBS drama series Downton Abbey, which brought the castle international fame. The increased numbers of visitors to the castle have allowed for repairs on Highclere's turrets and its interior. The family attributed this