African-American vets faced significant challenges when they came home particularly to the South. They would be frequently reminded that their status remained unchanged despite their service, and publicly wearing a uniform often led to violence. This was because wearing the uniform and highlighting honorable service during the war indicated they were worthy of respect, something anathema to Jim Crow.

The case of Isaac Woodard is a telling one. He was discharged from the Army in 1946 and was en route home on a Greyhound when he demanded the driver allow him to take a bathroom break. At the next stop the bus driver alerted the sheriff and deputies of a South Carolina town, who confronted, arrested, and beat Woodard. The assault left him blind and he sought justice. South Carolina refused to prosecute, but the federal government intervened since Woodard was in uniform at the time of the assault. The trial of Sheriff Shull was a farce, the jury deliberated for a half hour and even though the sheriff admitted to blinding Woodard, found him not guilty leading to applause from those in the gallery. Woodard's case enraged Truman, who made it the centerpiece of his argument for more federal involvement in civil rights issues. In a 1947 speech to the NAACP he argued that the US "cannot be content with a civil liberties program which only emphasizes the need of protection against the possibility of tyranny by the Government," a clear recognition that the tyranny of the majority or the masses posed an equal danger.

African-American veterans returning from Germany also noted a stark difference between their treatment overseas and at home. In Germany, they could often eat where they chose, interacted well with the German people, and even dated and married white German women. Upon return they faced a segregated south and defacto segregation in the north. JFK noted this treatment in his address on Civil Rights in 1963, noting that "when Americans are sent to Vietnam or West Berlin, we do not ask for whites only" and that as a result "It ought to be possible, therefore, for American students of any color to attend any public institution they select without having to be backed up by troops."

Thomas Borstelmann's Cold War and the Color Line, Mary Dudziak's Cold War Civil Rights, and Maria Hohn's GIs and Frauleins all deal with this topic to varying extents.

TLDR: Black veterans returning to the south faced increased risk of violence because of their service due to white fears that their honorable service would make them more likely to seek and receive equal treatment.