Peace & Justice History for 9/4:

https://www.peacebuttons.info/E-News/peacehistoryseptember.htm#september4

September 4, 1949
Paul Robeson, scholar, athlete, musician and leader, defying a racist and red-baiting mob, sang to 15,000 at a Labor Day gathering in Peekskill, New York.
 
Paul Robeson (at microphone) singing to the Labor Day gathering in Peekskill, New York
The story and photographs of what happened 
Film from that day narrated by Sidney Poitier 
September 4, 1954
The Peace Pledge Union (PPU) organized a demonstration against the H-Bomb in London’s Trafalgar Square.
The PPU dates back to October 1934.

Young Peace Pledge Union members today.
The PPU today
September 4, 1957
Elizabeth Eckford and eight other young Negroes were blocked from becoming the first black student at Central High School in Little Rock, Arkansas.

Governor Orval Faubus had called out the National Guard to prevent the court-ordered integration of the public schools in the state’s capital.
President Dwight Eisenhower eventually sent in federal troops to guarantee the law was enforced.

Elizabeth Eckford
Read more Elizabeth Eckford followed and taunted by mob, 1957.
A very interesting related story: 
September 4, 1970
Vietnam Veterans Against the War (VVAW) began Operation RAW (Rapid American Withdrawal). Over the following three days more than 200 veterans, assisted by the Philadelphia Guerilla Theater, staged a march from Morristown, New Jersey, to Valley Forge, Pennsylvania, reenacting the invasion of small rural hamlets along the way.

Operation Rapid American Withdrawal 1970-2005: An Exhibition: 
September 4, 1978
Simultaneous demonstrations in Moscow’s Red Square and in front of the White House in Washington, D.C. were organized by the War Resisters League, calling for nuclear disarmament.