In the summer of 1917, violent racial riots against blacks due to labor tensions broke out in East St. Louis, Illinois and Houston, Texas.

By 1919, an estimated 500,000 African Americans had emigrated from the Southern United States to the industrial cities of the Northeast and Midwest in the first wave of the Great Migration (which continued until 1940).

In rural Georgia, the riot of Jenkins County led to 6 deaths, as well as the destruction of various property by arson, including the Carswell Grove Baptist Church, and 3 black Masonic lodges in Millen, Georgia.

The National Conference on Lynching took place in Carnegie Hall, New York City, May 5–6, 1919. The goal of the conference was to pressure Congress to pass the Dyer Anti-Lynching Bill. It was a project of the new NAACP, which in April released a report, Thirty Years of Lynching in the United States, 1889-1918.

The Charleston riot resulted in the injury of 5 white and 18 black men, along with the death of 3 others: Isaac Doctor, William Brown, and James Talbot, all black. Following the riot, the city of Charleston, South Carolina imposed martial law. A Naval investigation found that four U.S. sailors and one civilian—all white men—initiated the riot.

In Vicksburg, 1000 white rioters broke Lloyd Clay out of jail, hung him, and burned him in the city center as the crowd watching. The riot spurred by rumors of an attack on a white women.

In May, following the first serious racial incidents, W. E. B. Du Bois published his essay "Returning Soldiers": We return from the slavery of uniform which the world's madness demanded us to don to the freedom of civil garb. We stand again to look America squarely in the face and call a spade a spade. We sing: This country of ours, despite all its better souls have done and dreamed, is yet a shameful land.… We return. We return from fighting. We return fighting.

At 1:00 AM on the morning of May 24, 1919, two white men, John Dowdy and Levi Evans went into the black section of Milan. They first tried to get into the home of Emma McCollers who had two young daughters. When the family refused to open the door Dowdy fired his gun. This caused the girls to flee to another house, the home of widow Emma Tisber. The two men followed and invaded the Tisber home and attempted to assault two young black girls. When the two girls attempted to hide under the porch, Dowdy and Evans began ripping up the floor to get to them. Washington, a black man, attempted to defend the girls and get the men to leave. Dowdy fired at Washington and after a struggle, Washington, who was 72 years old, shot and killed Dowdy. Washington went uptown and woke up the chief of police, Mr. Stuckey, who sent Washington to the McCrae jail at 2:00 AM May 24, 1919. There he stayed in jail until the 25th, at 12:00 PM, when a crowd of white men, led by a Baptist minister, removed Washington from the jail. To possibly hide their crimes all black residents of Milan were rounded up and ordered out of the town on the night of May 25th. At 2:00 AM on May 26th the lynch mob hung him from a post and shot him repeatedly until his body fell in pieces from the post. White residents rioted in the city, damaging and burning many black homes. They threatened black citizens, lest they dare to speak out about the events in public.

On May 30, 1919, about 20 sailors and soldiers were arrested by police officers, marines, and firemen. The Greeneville Daily Sun reported that the trouble began when "African American sailors" entered the Coast Guard Academy in New London and attacked white sailors. On June 29, 1919, another riot erupted which required the Marines to restore order.

John Hartfield left his home in Ellisville seeking a better life in East St. Louis. In 1919, he traveled back to Ellisville to visit his white girlfriend, Ruth Meeks, taking a job as a hotel porter in Laurel. When the relationship became known to some white men, they determined to kill Hartfield. They accused Hartfield of raping Meeks, who they claimed was 18, although she was actually in her mid-twenties. Hartfield managed to elude them for a while, but they pursued him for several weeks. Sheriff Allen Boutwell in Laurel raised donations to fund a hunting party with bloodhounds at the request of Sheriff Harbison. He was finally apprehended attempting to board a train on June 24, and was turned over to Sheriff Harbison, who placed him in the charge of a deputy and left town. The deputy immediately released him to a mob. Hartfield had been wounded, so a white doctor, A. J. Carter, treated his wounds to keep him alive long enough to be murdered. At 5:00 PM on June 26, 1919, a large cheering crowd assembled to watch the premeditated murder of John Hartfield.

A small disturbance occurred between black soldiers and white policemen, which ended quickly.

Local police in Bisbee, Arizona attacked the 10th U.S. Cavalry, an African-American unit known as the "Buffalo Soldiers," formed in 1866.

During a race riot local African-American, Rob Ashely, was accused in the murder of a white man and wounding another man on July 6, 1919. While in jail the local white community threatened to storm the jail and lynch Ashely. They were thwarted by an armed black community group that was formed to protect the jail and prevent a lynching. Later a company of eighty home guards prevented further trouble, but for weeks the situation was tense.

A white race riot in Longview, Texas led to the deaths of at least 4 men and destroyed the African-American housing district in the town.

On July 14, 1919, hundreds of white boys 16 to 19 years old converged on Garfield Park. There they used bricks and clubs to beat any blacks they came across. When a group of African-Americans took shelter in the house of Nathan Weather, a local black man, the white mob followed them and surrounded the house. Weather fired into the crowd in hopes of dispersing the mob. A seven-year-old onlooker, Charlotte Pieper, received a flesh wound from stray buckshot. Another youth, Paul Karbwitz, 18, was also hit. Police were eventually able to disperse the mob and quell the riot.

The Port Arthur riot happened on July 15, 1919, in Port Arthur, Texas. Violence started after a group of white men objected to an African American smoking near a white woman on a street car.

Claude McKay's sonnet, "If We Must Die", was prompted by the events of Red Summer.

The Washington race riot of 1919 was civil unrest in Washington, D.C. from July 19, 1919, to July 24, 1919. The race riot started on Saturday July 19 following an incident involving two African-American men and Elsie Stephnick, the white wife of an employee of the United States Naval Aviation Department. She was "jostled" near New York Avenue, and 15th Street Northwest. One of the men was arrested and questioned concerning an alleged sexual assault, but subsequently released. A mob of White Americans formed and started attacks on several African Americans and also an African-American family home.

On July 20, 1919, a White man and an African American man were arguing about World War I. The fight got heated and the black man pulled a gun and shot wildly down the street. Some of the bullets hit civilians, with one striking George Doles of 231 East 127th St while he was in his ground floor apartment. Another hit Henrietta Taylor, who was sitting on a stoop on 228 East 127th Street. While the two were rushed to a Harlem hospital, word spread that a riot was about to start, and when police arrived on the scene about a thousand black people were present on the block between 2nd and 3rd Ave. As police attempted to clear the streets they were fired upon from surrounding buildings.

The NAACP sent a telegram of protest to President Woodrow Wilson: The shame put upon the country by the mobs, including United States soldiers, sailors, and marines, which have assaulted innocent and unoffending negroes in the national capital. Men in uniform have attacked negroes on the streets and pulled them from streetcars to beat them. Crowds are reported have directed attacks against any passing negro.… The effect of such riots in the national capital upon race antagonism will be to increase bitterness and danger of outbreaks elsewhere. National Association for the Advancement of Colored People calls upon you as President and Commander in Chief of the Armed Forces of the nation to make statement condemning mob violence and to enforce such military law as situation demands.…

In Norfolk, Virginia, a white mob attacked a homecoming celebration for African-American veterans of World War I. At least 6 people were shot, and the local police called in Marines and Navy personnel to restore order.

The Newberry 1919 lynching attempt was the attempted lynching of Elisha Harper, Newberry, South Carolina on July 24, 1919. Harper was sent to jail for insulting a 14 year-old girl.

The Annapolis riot of 1919 took place on June 27, 1919, between midnight and 1 AM, in Annapolis, Maryland. A mob of African-American bluejackets from the U.S. Navy fought local Annapolis African-Americans.

Longstanding racial tensions between whites and blacks exploded in five days of violence that started on July 27, 1919. On that hot summer day, on a segregated Chicago beach, a group of white men stoned Eugene Williams to death when he crossed the unofficial barrier between the white and black sections of the 29th Street beach. Tensions escalated when a white police officer not only failed to arrest the white man responsible for Williams' death, but arrested a black man instead. Objections by black observers were met with violence by whites. Attacks between white and black mobs erupted swiftly. Because of the rioting, 38 people died (23 African American and 15 white), and another 537 were injured, two-thirds of them African American; one African-American Patrolman John W. Simpson was the only policeman killed in the riot.

The Syracuse riot of 1919 were a violent racial riot, on July 31, 1919, between white and black workers of the Globe Malleable Iron Works in Syracuse, New York.

All black residents were forced to leave the city.

On August 12, at their annual convention, the Northeastern Federation of Colored Women's Clubs (NFCWC) denounced the rioting and burning of negroes' homes, asking President Wilson "to use every means within your power to stop the rioting in Chicago and the propaganda used to incite such."

The Joint Legislative Committee to Investigate Seditious Activities, popularly known as the Lusk Committee, was formed in 1919 by the New York State Legislature to investigate individuals and organizations in New York State suspected of sedition. The committee was chaired by freshman State Senator Clayton R. Lusk of Cortland County, who had a background in business and conservative political values, referring to radicals as "alien enemies." Only 10% of the four-volume work constituted a report, while the rest reprinted materials seized in raids or supplied by witnesses, much of it detailing European activities, or surveyed efforts to counteract radicalism in every state, including citizenship programs and other patriotic educational activities. Other raids targeted the left-wing of the Socialist Party and the Industrial Workers of the World (IWW). When they analyzed the materials it hauled away, it made much of attempts to organize "American Negroes" and calls for revolutions in foreign-language magazines.

The Laurens County, Georgia race riot was an attack on the black community by white mobs in August of 1919. In the Haynes' report, as summarized in the New York Times, it is called the Ocmulgee, Georgia race riot. On Wednesday, August 27, a black man, chosen because he seemed like the leader of the local community was lynched and on Friday morning August 29, three black churches and one community building were burnt down. He was taken from Cadwell, Georgia and killed in Ocmulgee, Georgia. The corpse of an elderly man was later pulled from the ashes of the church burnt down in Ocmulgee. The body may have belonged to Eli Cooper who was alleged to have said that "the negroes had been run over for fifty years, but this will all change in thirty days." The local white community took this to mean a call for violent revolution.

At the end of August, the NAACP protested again to the White House, noting the attack on the organization's secretary in Austin, Texas the previous week. Their telegram read: "The National Association for the Advancement of Colored People respectfully enquires how long the Federal Government under your administration intends to tolerate anarchy in the United States?".

White mob dragged Lucius McCarty's body behind a car killing him before burning his corpse in a bonfire.

The Knoxville riot in Tennessee broke out after the arrest of a black suspect on suspicion of murdering a white woman. Searching for the prisoner, a lynch mob stormed the county jail, where they liberated 16 white prisoners, including suspected murderers. The mob attacked the African-American business district, where they fought against the district's black business owners, leaving at least 7 dead and wounding more than 20 people.

A black man named Ephram Gethers was shot by a police officer.

In September 1919, in response to the Red Summer, the African Blood Brotherhood formed in northern cities to serve as an "armed resistance" movement.

The Omaha race riot occurred in Omaha, Nebraska, September 28–29, 1919. The race riot resulted in the lynching of Will Brown, a black civilian; the death of two white rioters; the injuries of many Omaha Police Department officers and civilians, including the attempted hanging of Mayor Edward Parsons Smith; and a public rampage by thousands of white rioters who set fire to the Douglas County Courthouse in downtown Omaha.

On September 30, a massacre broke out against blacks in Elaine, Phillips County, Arkansas, being distinct for having occurred in the rural South rather than a city. The Elaine massacre or the Elaine race riot occurred on September 30–October 1, 1919, at Hoop Spur in the vicinity of Elaine in rural Phillips County, Arkansas. Although official records of the time state that eleven black men and five white men were killed, estimates of the actual number of black people who were killed range from 100 to 237. The white mobs were aided by federal troops (requested by Arkansas governor Charles Brough) and vigilante militias like the Ku Klux Klan.

A riot started by white Navy bluejackets against an entire black neighborhood was quickly quelled by the police.

The October 1919 report by Dr. George Edmund Haynes was a call to national action, was published in The New York Times and other major newspapers. Haynes noted that lynchings were a national problem. As President Wilson had noted in a 1918 speech: from 1889–1918, more than 3,000 people had been lynched; 2,472 were black men, and 50 were black women. Haynes said that states had shown themselves "unable or unwilling" to put a stop to lynchings, and seldom prosecuted the murderers. The fact that white men had been lynched in the North as well, he argued, demonstrated the national nature of the overall problem: "It is idle to suppose that murder can be confined to one section of the country or to one race."

During the Chicago racial violence against blacks, the press learned from Department of Justice officials that the IWW and Bolsheviks were "spreading propaganda to breed race hatred". FBI agents filed reports that leftist views were winning converts in the black community. One cited the work of the NAACP "urging the colored people to insist upon equality with white people and to resort to force, if necessary. J. Edgar Hoover, at the start of his career in government, analyzed the riots for the Attorney General. He blamed the July Washington, D.C., riots on "numerous assaults committed by Negroes upon white women". For the October events in Arkansas, he blamed "certain local agitation in a Negro lodge". A more general cause he cited was "propaganda of a radical nature". He charged that socialists were feeding propaganda to black-owned magazines such as The Messenger, which in turn aroused their black readers. He did not note the white perpetrators of violence, whose activities local authorities documented. As chief of the Radical Division within the U.S. Department of Justice, Hoover began an investigation of "negro activities" and targeted Marcus Garvey because he thought his newspaper Negro World preached Bolshevism. He authorized the hiring of black undercover agents to spy on black organizations and publications in Harlem.

Corbin, Kentucky race riot of 1919 was a race riot in 1919 in which a white mob forced nearly all the town's 200 black residents onto a freight train out of town, and a sundown town policy until the late 20th century.

On Sunday, November 2, 1919, Paul Jones allegedly attacked a white woman about 2 miles (3.2 km) outside of Macon. Paul Jones was chased through town until he was cornered in a rail boxcar, there the woman positively identified him. A white mob of 400 people quickly assembled and over the protests of Sheriff James R. Hicks they seized Jones. His body was riddled with bullets, "saturated with coal oil" and lit on fire. He was still alive as the flames consumed his body and the mob watched as he writhed in pain. There were no arrests.

African-American man, Jordan Jameson was lynched on November 11, 1919, in the town square of Magnolia, Columbia County, Arkansas. A large white mob seized Jameson after he allegedly shot the local sheriff. They tied him to a stake and burned him alive.

After accusing three black men of killing a police man, when the mob found out the brothers were out of their reach they turned their anger on the black community. One mob of 300 whites were rampaging through the black part of town when they encountered 4 black men, the two parties shot at each other and African-American Bannel Fields was wounded with a shot in the head.

On November 17, Attorney General A. Mitchell Palmer reported to Congress on the threat that anarchists and Bolsheviks posed to the government. More than half the report documented radicalism in the black community and the "open defiance" black leaders advocated in response to racial violence and the summer's rioting. It faulted the leadership of the black community for an "ill-governed reaction toward race rioting.… In all discussions of the recent racial riots against blacks there is reflected the note of pride that the Negro has found himself. that he has 'fought back,' that never again will he tamely submit to violence and intimidation". It described "the dangerous spirit of defiance and vengeance at work among the Negro leaders".

The Bogalusa saw mill killings was a racial attack that killed four labor organizers on November 22, 1919. It was mounted by the white paramilitary group the Self-Preservation and Loyalty League (SPLL) in Thibodaux, Louisiana. They were supported by the owners of Great Southern Lumber Company, a giant logging corporation, that hoped to prevent union organization and the Black and White labor organizations from merging.

Protests and appeals to the federal government continued for weeks. A letter from the National Equal Rights League, dated November 25, appealed to Wilson's international advocacy for human rights: "We appeal to you to have your country undertake for its racial minority that which you forced Poland and Austria to undertake for their racial minorities."