August 20
1866 – President Andrew Johnson formally declares the American Civil War over.
1920 – The first commercial radio station, 8MK (now WWJ), begins operations in Detroit.
1940 – In Mexico City, Mexico exiled Russian revolutionary Leon Trotsky is fatally wounded with an ice axe by Ramón Mercader. He dies the next day.
1986 – In Edmond, Oklahoma, U.S. Postal employee Patrick Sherrill guns down 14 of his co-workers and then commits suicide.
1991 – Dissolution of the Soviet Union, August Coup: More than 100,000 people rally outside the Soviet Union’s parliament building protesting the coup aiming to depose President Mikhail Gorbachev.
August 21
1770 – James Cook formally claims eastern Australia for Great Britain, naming it New South Wales.
1831 – Nat Turner leads black slaves and free blacks in a rebellion in Southampton County, Virginia, which will claim the lives of 55 to 65 whites.
1911 – The Mona Lisa is stolen by a Louvre employee.
1959 – United States President Dwight D. Eisenhower signs an executive order proclaiming Hawaii the 50th state of the union. Hawaii’s admission is currently commemorated by Hawaii Admission Day
1991 – Coup attempt against Mikhail Gorbachev collapses.
2017 – Great American Eclipse traverses the continental United States.
August 22
1642 – Charles I raises his standard in Nottingham, which marks the beginning of the English Civil War.
1922 – Michael Collins, Commander-in-chief of the Irish Free State Army, is shot dead in an ambush during the Irish Civil War.
1978 – The District of Columbia Voting Rights Amendment is passed by the U.S. Congress. The proposed amendment would have provided the District of Columbia with full voting representation in the Congress, the Electoral College, and regarding amending the U.S. Constitution. The proposed amendment failed to be ratified by enough states (ratified by 16, needed 38) and so did not become part of the Constitution.
1992 – FBI sniper Lon Horiuchi shoots and kills Vicki Weaver during an 11-day siege at her home at Ruby Ridge, Idaho.
August 23
1775 – American Revolutionary War: King George III delivers his Proclamation of Rebellion to the Court of St James’s stating that the American colonies have proceeded to a state of open and avowed rebellion.
1784 – Western North Carolina (now eastern Tennessee) declares itself an independent state under the name of Franklin; it is not accepted into the United States, and only lasts for four years.
1831 – Nat Turner’s slave rebellion is suppressed.
1990 – West and East Germany announce that they will reunite on October 3.
2011 – Libyan leader Muammar Gaddafi is overthrown after the National Transitional Council forces take control of Bab al-Azizia compound during the Libyan Civil War.
August 24
1814 – British/Canadian troops invade Washington, D.C. and during the Burning of Washington the White House, the Capitol and many other buildings are set ablaze.
1891 – Thomas Edison patents the motion picture camera.
1941 – Adolf Hitler orders the cessation of Nazi Germany’s systematic T4 euthanasia program of the mentally ill and the handicapped due to protests, although killings continue for the remainder of the war.
1998 – First radio-frequency identification (RFID) human implantation tested in the United Kingdom.
August 25
1814 – War of 1812: On the second day of the Burning of Washington, Canadian/British troops torch the Library of Congress, United States Treasury, Department of War, and other public buildings.
1948 – The House Un-American Activities Committee holds first-ever televised congressional hearing: “Confrontation Day” between Whittaker Chambers and Alger Hiss.
1950 – President Harry Truman orders the U.S. Army to seize control of the nation’s railroads to avert a strike.
August 26
1789 – The Declaration of the Rights of Man and of the Citizen is approved by the National Constituent Assembly of France.
1920 – The 19th amendment to United States Constitution takes effect, giving women the right to vote.
2009 – Kidnapping victim Jaycee Dugard is discovered alive in California after being missing for over 18 years.
Source