The answer provided by CalculatorUser is pretty much correct , but i would like to add some corrections according to myself.
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Subject:
The subject of the letter was to tell the clergymen his reason for why he had come to Birmingham. In the letter , he stated that he was here to achieve equal rights for the people whom were oppressed. He also stated that he was going to use nonviolent means such as protesting and negotiating to achieve his goal of equality.
Occasion:
Martin Luther King Jr. wrote this letter inside Birmingham jail because he was accused of his improper acts of civil disobedience. Dr. King was doing using these protesting techniques in order to express his disappointment at the people and laws who which were suppressing the black community. He wanted to fix the unjust actions that were implemented into in the society.
Audience:
Martin Luther King Jr. wrote the Letter from Birmingham jail as a response to eight clergymen’s statement in the local newspaper urging black people to withdraw their support from him and his demonstrations.
Purpose:
The purpose of writing the letter was to respond to the publishing in the local newspaper thom that was posted by eight clergymen in Alabama. The newspaper that the clergymen posted was asking Black’s black people to not change their current way of life, but to stay oppressed and submissive to the white man men. Dr. King’s response to the statement was that without any action , no result would occur , and so he wants them to take a stance without violence , as he believes that would only escalates the situation. It also explains his reasons for starting the civil disobedience. He wanted to change the way that people were treated all over the country and explains the horrible way that African Americans are were being treated.
Speaker
Martin Luther King Jr. is the speaker in the letter. He was a civil rights activist for many years and wanted to see all the people being treated equally.
Tone
The tone that is conveyed in the letter shifts and changes in order to match the words he was conveying at the time. He keeps a courageous and strong will throughout the speech and includes a dedication in areas such as his willingness to suffer for equality among people. He never changed the tone of the letter to anything of violence or hate. He always keeps a passive stance, a very peaceful one , in order to achieve his ultimate goal of equality among men in the country. The tone of the letter has also been changed to that of previous speeches and addresses. In , which this he writes wrote this to convey it to his audience which was who were primarily the reverends and pastors. Due to the limited religious practices , he includes many religious ideals in the letter to address these men personally.
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i tried my best , checking and rechecking it , i hope it helps to some extent.
I think you should ask your teacher about the 'tense' to use, for eg , in the 'purpose' para , past tense is used pretty much and in the 'tone' present tense is used , so it would help you to edit better if you do that. That way you wouldnt have to swing between deciding which tense should be applied where.
+11912 
