What event in 1959 changed the relationship between cuba and the united states

What was one effect of the emancipation proclamation on african americans in the north?

Dams are used for all of the following purposes except

After the success of the sputnik launch, the united states feared that they would never be able to launch their own satellite, the ussr had used technology developed by the united states, the soviets had superior nuclear capabilities, that any future us satellites would not be as successful.