in U.S. history). May 21 – New Zealand is declared a British colony. June 7 – On the death of Frederick William III of Prussia, he is succeeded on the throne of the Kingdom of Prussia (which he has ruled for more than 40 years) by his eldest son Frederick William IV. June 12–23 – The World Anti-Slavery Convention is organised by the British and Foreign Anti-Slavery Society, at Exeter Hall in London, England. Arguments over the exclusion of women from the convention have important ramifications for the movement for women's suffrage in the United States. July–September July 4 – The Cunard Line's 700-ton wooden paddlewheel steamer departs from Liverpool, bound for Halifax, Nova Scotia, on the first steam transatlantic passenger mail service. July 15 – The Austrian Empire, the United Kingdom, the Kingdom of Prussia, and the Russian Empire sign the Convention of London with the Sublime Porte, ruler of the Ottoman Empire. July 21 – August Borsig's steam locomotive, the first built in Germany, competes against a Stephenson-built locomotive on the Berlin–Jüterbog railroad; the Borsig locomotive wins by 10 minutes. July 23 Pedro II is declared "of age" prematurely, and begins to reassert central control in Brazil. The Province of Canada is created by the Act of Union. August 1 – The Slavery Abolition Act ends the slave trade in the United Kingdom. August 10 – Fortsas hoax: A number of book collectors gather in Binche, Belgium, to attend a non-existent book auction of the late Count of Fortsas. September 10 – Ottoman and British troops bombard Beirut, and land troops on the coast, to pressure Egyptian Muhammad Ali to retreat from the country. September 16 – Joseph Strutt hands over the deeds and papers concerning the Derby Arboretum, which is to become England's first public park. September 30 – The frigate Belle-Poule arrives in Cherbourg, bringing back the remains of Napoleon from Saint Helena to France. October–December October 7 – William II becomes King of the Netherlands. October 8 – A firman (imperial decree) of Sultan Abdulmejid I replaces Bashir Shihab II as Emir of Mount Lebanon with Prince Bashir Chehab III (Bashir Qasim al-Chehab). October 11 – Maronite leader Bashir Shihab II surrenders to the Ottomans, and on October 14 goes into exile, initially in Malta. November 4 – 1840 United States presidential election: William Henry Harrison defeats Martin Van Buren in a landslide. December 7