On the cold, snowy night of March 5, 1770, a mob of American
colonists gathered at the Customs House in Boston and began
taunting the British soldiers guarding the building.

The protesters, who called themselves Patriots, were protesting
the occupation of their city by British troops, who were sent to
Boston in 1768 to enforce unpopular taxation measures passed
by a British parliament that lacked American representation.

British Captain Thomas Preston, the commanding officer at the
Customs House, ordered his men to fix their bayonets and join
the guard outside the building.

The other soldiers began firing a moment later, and when the
smoke cleared, five colonists were dead or dying—Crispus
Attucks, Patrick Carr, Samuel Gray, Samuel Maverick and
James Caldwell—and three more were injured.

Although it is unclear whether Crispus Attucks, an African
American, was the first to fall as is commonly believed, the
deaths of the five men are regarded by some historians as
the first fatalities in the American Revolutionary War.

During the 1972 Summer Olympics at Munich, in the early
morning of September 5, a group of Palestinian terrorists
stormed the Olympic Village apartment of the Israeli athletes,
killing two and taking nine others hostage.

The terrorists were part of a group known as Black September,
in return for the release of the hostages, they demanded that
Israel release over 230 Arab prisoners being held in Israeli jails
and two German terrorists.

In an ensuing shootout at the Munich airport, the nine Israeli
hostages were killed along with five terrorists and one West
German policeman. Olympic competition was suspended for
24 hours to hold memorial services for the slain athletes.

Black September terrorist looks from the balcony of an apartment where Israeli Olympic team members are held hostage.

With terrorists holed up in the Israeli athletes’ quarters,
swarms of German policemen, in uniform and plain
clothes, move in and seal off the area.

A German policeman leans against a wall outside the
apartment.

On May 4, 1970, in Kent, Ohio, 28 National Guardsmen fired their weapons at a group of anti-war demonstrators on the Kent State University campus, killing four students, wounding eight, and permanently paralyzing another. The tragedy was a watershed
moment for a nation divided by the conflict in Vietnam, and
further galvanized the anti-war movement. 

On April 20, 1999, two teenage gunmen killed 13 people in a
shooting spree at Columbine High School in Littleton,
Colorado, south of Denver.

At approximately 11:19 a.m., Dylan Klebold, 17, and Eric Harris,
18, dressed in trench coats, began shooting students outside
the school before moving inside to continue their rampage. By
11:35 a.m., Klebold and Harris had killed 12 fellow students and
a teacher and wounded another 23 people. Shortly after noon,
the two teens turned their guns on themselves and died by
suicide
  .

The event prompted a national debate on gun control and school
safety, as well as a major investigation to determine what
motivated the teen gunmen. In the days immediately following
the shootings, it was speculated that Klebold and Harris
purposely chose jocks, minorities and Christians as their
victims.

An armed group of white supremacists attacked a courthouse
guarded by a mostly-Black militia in the town of Colfax,
Louisiana on April 13, 1873. A bloodbath ensued, as the
militia surrendered and the white supremacists carried out a
day-long campaign of terror that came to be known as the
Colfax Massacre.