On June 16, 1976 the Soweto Students Uprising began (Soweto is a neighborhood of Johannesburg). Around 20,000 students went to the streets and made a peaceful protest opposing to Afrikaan as the official language for instruction in schools. The government's responde was violence, killing hundreds of students, as a result, the revolt spread through the whole country and carried on until the following year. These events changed the socio-political landscape in South Africa which main problem was the Apartheid.
They were most likely feeling proud spirtual and happy
This is shown in this part of the hymn.
Glory! Glory! Hallelujah! Glory! Glory! Hallelujah
Glory! Glory! Hallelujah! His truth is marching on
The first ten amendments are known as the Bill of Rights, becoming part of the constitution Dec. 15, 1791.
It was called the Warsaw Pact.