difficult task. Both Jem and Scout gain valuable insights about their racist community and begin to perceive the overt hypocrisy throughout Maycomb. In addition to developing their perspective and losing their childhood innocence, the Tom Robinson trial also makes Jem and Scout more tolerant and sympathetic toward innocent, defenseless individuals. Overall, the Tom Robinson trial is a significant moment in the lives of Atticus, Jem, and Scout and affects how the Finch children perceive their prejudiced small town.

In regards to the verdict, there is one thing that is significant for this time period.  The all white jury does find him to be guilty, which is really no surprise. The importance of their verdict is that the jury actually considered the case before immediately finding him guilty. The jury deliberated for an unusually long period of time, well into the late evening. The fact that the certain jurors needed convincing before immediately subscribing to a guilty vote shows progress in this largely racist community. Some interpret this as progress toward the equal treatment of African-Americans in a criminal case for the Maycomb community.

Tom Robinson's sentence is never actually revealed in the book. A sentence is the term in prison or the announcement of the punishment. We do know he was taken to a prison because we hear second hand about how he was shot at.

I assume you are asking about the verdict (the decision the jury came to) which was guilty. The other editors have addressed that. If you do indeed mean the term sentence, I think what's important about it is that he never got to serve it. Before there was even a chance for appeal, before the sentence was revealed, Tom was killed. I guess you could say that his sentence ended up being the death penalty unjustly applied. This is important because it demonstrates the deep seeded racism at work in the South in the 30s.

A not guilty verdict in the Tom Robinson trial would have been an extraordinarily rare event in 1930s Alabama. As Atticus pointed out in To Kill a Mockingbird, no one could really expect an all-white jury to take the word of a black man (Tom) over that of a white man (Bob Ewell). Atticus realized he had little chance of acquittal at trial, but he hoped to eventually have the verdict overturned on appeal. Had Tom been found innocent of the charges against him, it would have been a major step in racial justice for a Deep South state.

In To Kill a Mockingbird, Mr. Bob Ewell, the town drunk, has accused Tom Robinson of raping his daughter, Mayella Ewell, and beating her in the process as well. Mr. Tate claims that he found Mayella with her right eye blackened, bruised arms, and finger marks all around her neck indicating that she had been choked. 

During the court proceedings, Atticus tricks Mr. Ewell into demonstrating that he is left-handed and not ambidextrous; the injuries on Mayella's right side could only correlate with a left-handed person. Atticus' suspicions that it was Mr. Ewell who beat his own daughter are confirmed when Tom's deformity is revealed to the court: 

His left arm was fully twelve inches shorter than his right, and hung dead at his side. It ended in a small shriveled hand, and... it was of no use to him. 

This is significant to his trial because it would have been physically impossible for Tom to do the things accused of him when his arm was crippled in such a manner.

We learn the truth of what happened from Tom's testimony: Mayella, "the loneliest person in the world," made sexual advances towards Tom. Tom was in the habit of regularly helping Mayella with chores. After luring him into the cabin with a request to help her with something, Mayella grabbed Tom around the waist and started kissing him. Tom tried to escape, but Mr. Ewell spotted the two and beat the girl himself after calling her a "whore." 

In Chapter 18, Atticus has Tom Robinson stand up in order to have Mayella look at him and identify him as the man she accuses of attacking her. Significantly, "His left arm was fully twelve inches shorter than his right, and hung dead at his side. It ended in a small shriveled hand, and from as far away as the balcony I [Scout)] could see that it was of no use to him." He had caught his left arm in a cotton gin when he was a boy. It appeared that Tom could not have inflicted Mayella's facial injuries with his right hand and it seemed obvious that she must have been beaten by someone else, presumably her own father. It also seemed impossible that Tom could have choked her or raped her, as she claimed, with only one good arm and hand.

First of all, Tom's trial is tied to the theme of the racism that existed during this time, especially in the South. The fact that Tom is innocent and Atticus proves it shows the extent of the racist attitudes that prevailed throughout American society. The whites on the jury would rather find a black man guilty than to believe that Mayella, a white woman, lied about what Tom did. This also shows the injustice of the justice system. Tom does not get a fair trial, and Atticus knows at the outset that Tom will not be fairly treated. Tom is not judged by a jury of his peers because there are no black people on the jury. Atticus defends Tom, knowing he would most likely lose the case, because Atticus cannot stop trying to get the same justice for blacks that white people enjoy. If no one ever tries to change society, then society will never change. Change usually doesn't happen overnight, and Atticus feels his defense of Tom is a small step toward equal rights and equal justice before the law for blacks.

Tom Robinson and Boo Radley are the characters of the title. Atticus tells Jem and Scout that it's not right to kill a mockingbird because it only brings joy to people with its song and does no harm to anyone. Tom Robinson is one of the mockingbirds of the story, and his conviction and subsequent death are a sin because Tom is innocent.