October 27

312 – The night before engaging in battle against Roman co-emperor Marcus Maxentius, Constantine sees a vision in the sky -a cross – and the words Ἐν Τούτῳ Νίκα “In this [you shall] conquer“, more well known in Latin; ‘IN HOC SIGNO VINCES‘ and paints it on the shields of his soldiers.

939 – Æthelstan, the first king of all England, dies

1553 – Physician Michael Servetus is burned at the stake at Geneva, for attacking trinitarian Nicene doctrines.

1682 – Philadelphia is founded in the Commonwealth of Pennsylvania.

1775 – King George III declares a Proclamation of Rebellion in the Thirteen Colonies at Parliament.

1795 – The United States and Spain sign the Treaty of Madrid, which established the boundaries between Spanish colonies and the states

1810 – The United States annexes the former Spanish colony of West Florida.

1838 – Missouri governor Lilburn Boggs issues the Extermination Order, which orders all Mormons to leave the state or be killed.

1904 – The first underground New York City Subway line opens, later designated as the IRT Broadway–Seventh Avenue Line.

1936 – Mrs. Wallis Simpson divorces her husband, which allows her to marry King Edward VIII, resulting in him abdicating the throne and changing world history.

1954 – Benjamin O. Davis, Jr. becomes the first African American Brigadier General in the U.S. Air Force.

1961 – NASA tests the first Saturn I rocket in Mission Saturn-Apollo 1.

1962 – During the Cuban Missile Crisis:
Major Rudolf Anderson of the U. S. Air Force becomes the only direct casualty of it when his U-2 airplane is shot down over Cuba
This is because, Senior Lieutenant Vasily Arkhipov, executive officer of the Soviet Foxtrot Class submarine B-59, and Chief of Staff of the submarine flotilla assigned to the area, refused his Captain’s independent order to launch a nuclear torpedo at the U.S.’s naval blockading fleet.

1964 – Ronald Reagan launches his political career by delivering a speech on behalf of Republican candidate for president, Barry Goldwater.

1988 – President Ronald Reagan suspends construction of the new U.S. Embassy in Moscow due to Soviet listening devices being found in the building structure.

1997 – A  financial crisis in Asian markets causes a crash in the Dow Jones Industrial Average of 554 points, or 7.18% of its value, at the time, the 12th largest percentage drop in its history.

2004 – The Boston Red Sox defeat the St. Louis Cardinals to win their first World Series in 86 years.

2018 – A gunman opens fire on a Pittsburgh synagogue killing 11 people and wounding another 6  before surrendering after being shot while engaging police in a gunfight.

2019 – Abu Bakr al-Baghdadi, self proclaimed caliph of the Islamic State,  commits suicide by blowing himself up instead of being captured by U.S. Army Special Operations Forces near Barisha, Syria.