What had Judge Taylor specifically done to try to help Tom? What did this mean to Maudie?

I think he specifically asks Atticus to defend Tom. He knew that Tom's only shot at getting justice in the racist South was using Atticus to defend him. Miss Maudie really admired Atticus for taking the case. 

Judge Taylor specifically asks Atticus to defend Tom because he knew Tom could have been innocent and he knew that Atticus would do anything he could to help Tom prove that he was in fact innocent.