According to Atticus in To Kill a Mockingbird, what is the only thing in which the people of this country are truly equal?
"But there is one way in this country in which all men are created equal—there is one human institution that makes a pauper the equal to a Rockefeller, the stupid man the equal of an Einstein, and the ignorant man the equal of any college president. That institution, gentlemen, is the court. . . . Our courts have their faults, as does any human institution, but in this country our courts are the great levelers, and in our courts all men are created equal."
This quoted passage is the second-to-last paragraph in Atticus's closing remarks for the trial of Tom Robinson. Unfortunately, his remarks are not enough to convince twelve white men to free an innocent black man of being accused of raping a white woman.
Atticus goes on to say that people may not have been born under equal circumstances, but they should be able to get an equal and fair trial without the pressures of social traditions, such as racism, influencing the facts. If there's no evidence to support the claims of an ignorant and uneducated white girl, then the black man should not have to take the blame for her indiscretions. Atticus even points out that Mayella is the one at fault and to blame for the whole trial.
If there is no place, asserts Atticus, for any person in the United States of America to go for a fair trial, then the premise upon which the country was founded is void. If the jury does not acquit Tom, it's as if they refuse to uphold the standards and principles of their nation. Sadly, that's exactly what they do: The jury fails to uphold those principles and they fail to make the court a place for people (mostly African-Americans) to find succor from the great equalizer of its citizens.
Atticus Finch, in Harper Lee’s To Kill a Mockingbird, states that the courts are the one place in this country in which all people are created equal. He also states that in his opinion, this belief is a reality separate from his--or any one person's--opinion:
...no ideal to me, it is a living, working reality.
For Atticus, the courts really are a place where all can seek justice with equal standing before the law. However, Atticus also knows that it is not really possible for all courts to live up to the standard of equality. He also admits the fallibility of the court system later in the paragraph when he says that the equality in court depends upon the soundness of its jury:
A court is only as sound as its jury, and a jury is only as sound as the men who make it up ... in the name of God, do your duty.
Atticus, despite his statement about the position of the court as an institution of equality, knows that the men who will decide Tom Robinson’s fate are not flawless and are subject to the prejudices and hatreds of their time and place. The fact that he invokes God at the end of his summation indicates that he believes it will take more than the usual human judgment to get his client a fair verdict based upon equal justice.
In effect, Atticus is stating that men are equal before the courts but that because of the prejudices of the people who make up the jury, the verdict may not reflect that equality.
Although the Declaration of Independence states that "all men are created equal," Atticus understands that this is a truth that is not truly believed or applied. He witnesses this contradiction to truth first-hand in Maycomb on a daily basis, and he has seen it during the trial of Tom Ronbinson. He tells the jury that not all are created equal in the traditional sense:
"We know all men are not created equal in the sense some people would have us believe..."
Atticus also tells the jury in Chapter 20 of To Kill a Mockingbird that the prosecution and witnesses (aside from Sheriff Heck Tate) who presented evidence were "confident" that the jury would agree that all "Negroes are basically immoral":
"... go along with them on the assumption--the evil assumption--that all Negroes lie, that all Negroes are basically immoral beings, that all Negroes are not to be trusted around our women..."
But, Atticus assures the jury, there is one system in which all men are accepted as equal. It is an American institution that makes wealthy men, paupers and the ignorant all equal.
"That institution, gentlemen, is a court."
Atticus upholds his assertion that the court is, separate from opinion or belief, a place of equal treatment for all.