This week, mental_floss is running a series about Abraham Lincoln's adventures as a young man, before he got into politics. In part one, we learn about a murder in Illinois. What does that have to do with Lincoln? We find out in part two, in a story of a wrestling match between Lincoln and another young man that linked the parties together. In part three, Lincoln the lawyer argues for the defense in an unorthodox but memorable manner. What happened then? Find out how all of this affected Lincoln's political career, in part four.