Miranda V. Arizona was a case that transformed the rights of the accused. Because of this case, when someone gets arrested, the police officer doing the arresting has to read aloud their "Miranda Rights" such as "You have the right to remain silent" "You have the right to an attorney, if you can not get one, one will be provided" etc.
Gideon V. Wainwright also transformed the rights of the accused by enforcing the 6th amendment unlike before. It made sure everyone, even those of lower economic status, can be represented by an attorney in court.
