What does To Kill a Mockingbird reveal about America? Is it still relevant in America today?

Many issues depicted in To Kill a Mockingbird are still relevant today—even though the novel was written in the 1960s and set in the 1930s.  The problems of the 1930s and the 1960s are still problems today: we have not wiped out racism or elitism, and we still struggle with treatment of those who are mentally ill.  In short, the US still has many problems with what we now refer to as hate crimes (even if that terminology would not have been used in the 1930s). A 2016 Federal Bureau of Investigation report "reveals 5,850 criminal incidents and 6,885 related offenses that were motivated by bias against race, ethnicity, ancestry, religion, sexual orientation, disability, gender, and gender identity."  In To Kill a Mockingbird, obviously race bias takes center stage, but it is not the only problem that receives attention.  

Ancestry is a cause of misunderstanding and profiling in To Kill a Mockingbird.  The Finch family heritage is highlighted in the text, and the reader is able to infer that Atticus is considered an oddity in his family's proud lineage.  Specifically, Atticus's parenting style is not acceptable to Aunt Alexandra, who leaves her genteel family property to come provide what she considers a "proper" feminine role model for Scout.  On the other side of the ancestry equation, Mayella Ewell's heritage is a burden. She is expected to do very little to advance her station in life because of her family's dysfunction.  Atticus is expected to do more, and Mayella is expected to do no more.

Arthur "Boo" Radley is mistrusted and feared because of his unnamed mental disability. In their fear of the unknown, the citizens of Maycomb have made him into a pariah.  Even Atticus's wisdom can go only so far in Radley's case.  Atticus thinks it would be a kindness to leave Arthur Radley alone, but solitude does not address whether Arthur could be helped or not.  Yes, Boo Radley seems to want to keep to himself, but it is hard to say whether that is his actual nature or whether it is a defense mechanism against a hateful world that has showed him very little acceptance in the past.

Even just a brief examination (such as the one above) shows that To Kill a Mockingbird presents issues that have not gone away in over fifty years.  The issues of ancestry and mental illness are both hooks for a modern reader to consider when reading To Kill a Mockingbird.  They mattered in the 1930s and the 1960s--and they still matter today.