The African people were elated because the colony mother's (The countries that colonized them) would not be imposing on their lives and would be able to create their own governments and laws.
On 28 August 1963, more than 200,000 demonstrators took part in the March on Washington for Jobs and Freedom in the nation's capital. The march was successful in pressuring the administration of John F. Kennedy to initiate a strong federal civil rights bill in Congress.
I'm assuming you mean the know-nothing party, and the founder of it is:
Lewis Charles Levin
A foreign policy challenge the US was faced with was the containment of communism in Asia and Europe, effected countries that concerned us more specifically were China, Germany, and later on Cuba. So the challenge was giving aid to countries that were forcefully communist (germany).