In his closing statement, Atticus says all men are created equal. What is the institution in which this is true?

From the text:

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."