Answer:
Symbolism
Explanation:
The speech is an example of symbolism. Symbolism is the use of symbols to present and stress a point. Symbolism is when one thing stands for or represents the other. For example, the person might say:
The project is likened to a white elephant - a costly but unnecessary thing.
In the statement, the freedom promised to black people is likened to a check that was supposed to bring joy but in turn, brings nothing. In other words, the black Americans were promised virtual freedom - non-existent freedom.