The robber Barons became rich by building monopolies. Option D is correct.
"Robber baron" is a derogatory metaphor of social criticism which was first refered to some late 19th-century American businessmen who were accused of using unscrupulous methods in their attempt to become wealthy, or expand their wealth.
The metaphor became popular as early as February 9, 1859, when The New York Times employed it to describe the business practices of Cornelius Vanderbilt.
Lincoln was supporting Wilmot Proviso, which was a failed attempt to ban slavery.
When Abraham Lincoln and Stephen A. Douglas met in a series of seven debates as they ran for Illinois Senate seat, they heatedly debated a critical issue that day, slavery.
Debates raised Lincoln's profile, helping to encourage him to run for president two years later.
However, Douglas will actually win the 1858 Senate election.
