I know this is quite oddly specific, but I was reading about various desegregation incidences in the US, and here it claims that when Eisenhower ordered the 101st Airborne Division to Little Rock, they went without their black soldiers.
To me it seems a very odd decision - surely not taking the Black soldiers is just another example of pointless segregation. Both the black and white children at school (and perhaps even families) could have taken note of normal, functional desegregated troops.
According to this army.mil article, it was to decided that the black troops were to stay in reserve to abate the anger of the crowd.
Although the Army finished integrating in 1954, it was decided that any black troops, including Command Sgt. Maj. Brown, who deployed to Little Rock would stay in the reserve force to abate the anger of the crowd.
They had very few racial problems within the unit, but he said many of the black 101st Abn. Div. Soldiers resented not being able to go into the school, but recalled the words of his commander, who told the back-up force that the most important thing was getting those kids to school.
"If the second force would've gone in there, we probably would have seen a lot of problems," Command Sgt. Maj. Brown said.
Followup question: Are there any references to the black soldiers' reaction, either at the time or when (according to OP's Wikipedia link) they were integrated into the units a month later?