April 18 Roland Garros 1775 – American Revolutionary War: Colonists Paul Revere and William Dawes, later joined by Samuel Prescott, began a midnight ride to warn residents of Lexington and Concord, Massachusetts, about the impending arrival of British troops. 1881 – The painted ceilings of the Natural History Museum, London, were unveiled when the building opened its doors to the public. 1915 – World War I: Hit by ground fire, French aviation pioneer Roland Garros (pictured) landed his aircraft behind enemy lines and was taken prisoner by German forces. 1949 – The Republic of Ireland Act 1948 came into force, describing Ireland as a republic and ending its membership in the Commonwealth of Nations. 1975 – Aryabhata, India's first satellite, was launched from Kapustin Yar in the Soviet Union. Ippolita Maria Sforza (b. 1445)Polydore Vergil (d. 1555)Jean Guillou (b. 1930)Albert Einstein (d. 1955) More anniversaries: April 17 April 18 April 19 Archive By email List of days of the year About