Amos
Amos was a rough farmer from a small town called Tekoa which was in Judah 6 miles south of Bethlehem and 11 miles from Jerusalem. Amos was unlike most other prophets, he wasn't apart of a priestly family as the like of Jeremiah and Ezekiel were, he also wasn't a man of the court like Isaiah was. Amos in many minds was considered as just an ignorant farmer. God however chose him and pulled him out of the pasture and sent him into Bethel to try to fix the king of Israel's violent, immoral, unrighteous society - he was sent to remind the rich and powerful of God's requirement for justice. Amos simply couldn't understand the people of Israel at the time, how certain people looked at themselves like they were better than others. He didn't understand how some people could just push the weak and poor to the side and trample over them like they were nothing. He warned, "Seek the Lord and live, or else he will sweep like fire through Israel."
Amos' message was very clear and direct, he was saying that if the people of Israel change their ways and better themselves that the Lord will restore Israel, it's a message of hope. But at the same time it was a message of destruction. He prophesied that Israel and many of it's neighbors would suffer because they broke a moral code overseen by the Lord, those such as Damascus, Gaza, Edom, Ammon, Moab, and Tyre, but his prophecy said that Israel and Judah would suffer the worst. He prophesied that the kingdom of Israel would be destroyed. Because of this his message was understandably not welcomed in Israel. So naturally, Amos was called a traitor of his homeland and kicked out of the capital.
His prophecies of destruction were conflicting with the current way the things in Israel seemed to be going, everything seemed to be going the right way. Under the leadership of their current king, Jeroboam II, Israel had extended its territory into modern day Syria. Israel's resultant affluence was the reason of Amos's mission as a prophet.
The exact time that Amos came forward with his prophecy isn't for sure, this is what the book of Amos read: "...The vision came to him at the time Uzziah was king of Judah, and while Jeroboam (son of Joash) was king of Israel - two years before the earthquake". Uzziah ruled over Judah from 792 until 740 b.c and Jeroboam II ruled over Israel from 793 until 753 b.c. So it's safe to say that Amos came out with his prophecy sometime between the years 792 b.c and 753 b.c.
Amos was straightforward and direct with the messages God gave him to preach. All of his prophecies are categorized in his own book in the bible which is simply the book of Amos. The book of Amos is one of the later books in the Old Testament, it's immediately after the book of Joel and right before the prophet Obadiah's book.

