This is in the United States, during segregation.

The little girl in the picture is Ruby Bridges. In 1960, she was one of the first Black kids to integrate a school. In this picture, she is walking to an all-Whites school and the guards are protecting her because the racist white adults wanted to harm her just for wanting to go to school.

Ruby Bridges is still alive today.

Basically the US government decided to de-segregate schools in order to counter the "malign influence" of Soviet "lies" that the US is an apartheid state, but soon realized that the people were so racist that the black schoolchildren needed federal agents as personal bodyguards to prevent lynchings.