Answer:
The speech "House Divided" is considered a seminal text because it changed the way the public and political leaders discussed slavery, and helped Lincoln gain national respect and became part of his successful presidential campaign.
Step-by-step explanation:
The House Divided speech was delivered by Abraham Lincoln on June 16, 1858, in Springfield, by accepting the nomination of the Illinois Republican Party to run for the Senate. The speech became the basis of his campaign against Stephen A. Douglas, with whom he debated before the election, and by whom he was ultimately defeated in the Senate race. It also became the basis of his presidential campaign of 1860.
Lincoln's lecture became a lasting picture of the danger of disunity caused by slavery, and served as a communion for the republicans of the northern states. Along with the speeches of Gettysburg and his second inauguration address, they form his three most important and well-known lectures.