Answer: Keeping Americans safe from other Americans
Step-by-step explanation:
In 1954 the Supreme Court ruled that segregation in public schools was against the Constitution and so the NAACP went ahead to enrol certain black students in previously white only schools.
One of the places they did this was in Little Rock, Arkansas. There was a lot of opposition to the children attending school and the Governor of Arkansas called in the National Guard to prevent the children attending.
President Eisenhower then sent in Federal troops and federalized the Arkansas National Guard and charged them with protecting the black children and ensuring that they attend. The National Guard therefore protected the children and in doing so protected Americans from other Americans.