You might want to review your history from the 60's. There's a long, long list of outbreaks of violence all over the country. The sparks that ignited most of them were in protest of police brutality, poverty, racial discrimination, and the assassination of the leaders who attempted to seek justice and change via peaceful means. Similar events and similar sparks occurred in the 80's in England and in the early 2000s in Australia.
Rochester 1964 race riot
24-26 July 1964
Philadelphia 1964 race riot
28-30 August 1964, Philadelphia, Pennsylvania, USA, Allegations of police brutality sparked the Columbia Avenue race riots.
11 August 1965, Los Angeles, California, USA, The McCone Commission investigated the riots finding that causes included poverty, inequality, racial discrimination and the passage, in November 1964, of Proposition 14 on the California ballot overturning the Rumford Fair Housing Act, which established equality of opportunity for black home buyers.
18 July 1966, Cleveland, Ohio, USA, The underlying causes of the riots may found in the social conditions that exist in the ghettos of Cleveland.
Racial tension in Omaha, Nebraska
5 July 1966, North Omaha, Nebraska, USA, More than 500 black youth gathered to protest the absence of recreation programs and jobs storm a local business district, throwing rocks and bricks at Jewish-owned businesses in the area. The National Guard is called in after three days of random violence and organized raids.
1967 Newark riots
12 July 1967, Newark, New Jersey, USA, Factors that contributed to the Newark Riot: police brutality, political exclusion of blacks from city government, urban renewal, inadequate housing, unemployment, poverty, and rapid change in the racial composition of neighborhoods.
1967 Plainfield riots
14 July 1967, Plainfield, New Jersey, USA
12th Street riot
23 July 1967, Detroit, Michigan, USA, The origins of urban unrest in Detroit were rooted in a multitude of political, economic, and social factors including police abuse, lack of affordable housing, urban renewal projects, economic inequality, black militancy, and rapid demographic change.
Minneapolis-Saint Paul, USA, Fall 1967
Racial tensions boil over in North Minneapolis as whites continue to leave the decaying core of the inner city bound for the suburbs.
1968 Chicago, Illinois riots
In Chicago, violence erupted in the black ghetto on the west side, eventually consuming a 28-block stretch of West Madison Street. Looting and arson took place primarily in the corridor between Roosevelt Road on the south and Chicago Avenue on the north.
1968 Washington, D.C. riots
4 April 1968, Washington, D.C., USA, A report from National Advisory Commission on Civil Disorders identified discrimination and poverty as the root causes of the riots that erupted in cities around the nation during the late 1960s and in Washington, DC in April 1968
Baltimore riot of 1968
4 April 1968, Baltimore, Maryland, USA
23 July 1968, Cleveland, Ohio, USA, Shootout between black militant organization led by Ahmed Evans and Cleveland Police Department attracted large and hostile black crowds that caused a 4 day long riot
June 1969, New York, New York, a turning point for the modern gay rights movement
1969 North 24th Street Riots
24 June 1969, North Omaha, Nebraska USA, An Omaha police officer fatally shoots a teenager in the back of the head during a gathering of youth in local public housing projects. Many youth and adults from the local African American community gather in the local business district, routinely burning and otherwise destroying non-Black-owned businesses.