June 21st

2009
Greenland assumes self-rule. The island had been administered by Denmark (earlier Denmark-Norway) for centuries. The Self-Government Act grants Greenland full responsibility for its inner affairs, while Denmark retains control of foreign policy.
2004
SpaceShipOne completes the world's first manned private spaceflight. The privately funded spaceplane reached an altitude of just over 100 kilometers (62 miles). Mike Melvill was the pilot and only occupant.
1997
The WNBA made its debut.
1993
English mathematician Andrew Wiles proves last theorem of Fermat.
Wiles's proof of Fermat's Last Theorem
1990
7.7 Manjil-Rudbar Earthquake with hundreds of aftershocks hits Iran, killing about 50,000.
2002 Bou'in-Zahra earthquake
1989
The U.S. Supreme Court decided that burning the U.S. flag was protected under the First Amendment.
Texas v. Johnson
1985
The body of Josef Mengele is identified. An international team of scientists confirmed that the skeletal remains found in a cemetery in Embu, Brazil are those of the Nazi war criminal. Mengele was a physician in the Auschwitz concentration camp and conducted horrific experimtents on some of the inmates.
Josef Mengele
1982
John Hinckley was found not guilty by reason of insanity for the attempted murder of President Ronald Reagan.
John Hinckley Jr.
1964
Three civil rights workers—James E. Chaney, 21, Andrew Goodman, 21 and Michael Schwerner, 24—disappeared in Philadelphia, Miss. In 2005, 41 years after the disappearance, Edgar Killen was convicted of their murders.
Murders of Chaney, Goodman, and Schwerner
1963
Cardinal Giovanni Battista Montini becomes Pope Paul VI. The Italian pontiff is known for completing the Second Vatican Council, addressing the Roman Catholic Church's relationship with the modern world.
Pope Paul VI
1948
Lord Mountbatten resigns as Governor General of India (formerly the last Viceroy).
Louis Mountbatten, 1st Earl Mountbatten of Burma
1895
The Kiel Canal is opened by German Emperor Wilhelm II. The 98 km (61 mi) long canal in Northern Germany is one of the world's busiest artificial water ways. It connects the North Sea with the Baltic Sea.
Kiel Canal
1854
First Victoria Cross won during bombardment of Bomarsund in the Aland Islands (Crimean War).
Battle of Bomarsund
1834
Cyrus McCormick's mechanical reaper was patented.
Cyrus McCormick
1788
The U.S. Constitution went into effect when New Hampshire became the 9th state to ratify it.
Timeline of drafting and ratification of the United States Constitution ...
1527
Italian statesman, diplomat, and author of “The Prince,” Niccolo Machiavelli died.
Niccolò Machiavelli