Final answer:
The author is using the literary technique of rhetoric in Lincoln's Second Inaugural Address.
Step-by-step explanation:
The literary technique used in Lincoln's Second Inaugural Address is rhetoric. Rhetoric is the art of effective or persuasive speaking or writing, using various techniques to appeal to emotions, reason, or morals. In his address, Lincoln used rhetorical devices such as parallelism, repetition, and emotional appeals to convey his message of unity, reconciliation, and the need for healing after the Civil War.