The quote means that Atticus is a great man who stands behind what he says and does, behaving the same in public as he does in his home. Unlike him, the others are two-faced, for example, publicly attacking Tom Robinson, while believing in the comfort of their homes that he might be innocent.
It was marked by grace, civility, & social conscience.
A biography can contain almost anything about a person- Their entire life, or just one key event... Most biographies, regardless of their length and target audience, will provide basic facts like the time and place in which the person lived.
