Despite his lack of an education and impoverished early life Andrew Johnson eventually developed a knack for political debate which led him to Senate and House of Representatives before serving as the Governor of Tennessee and ultimately the President of the United States. Johnson gained early notoriety when in 1862 at the beginning of the Civil War he was the only Southern member of Congress not to quit his post in Washington and instead opposed the secession. Despite calls from his secessionist constituents that he back down from his position Johnson held his ground even after he was beaten nearly to death in Virginia on a trip to his home state of Tennessee.
Following Lincoln's assassination the Republicans had high hopes for Johnson. He had shown a hatred for treason and a love for discipline when he was appointed the military governor of Tennessee after Lincoln took Nashville in the war. Instead Johnson did anything but help with the reconstruction in the south. Instead he let the southern states decide for themselves how they'd like to be rebuilt. This led to a lackluster reconstruction in which the southern states created laws making African-Americans a perpetual underclass.
The story isn't over yet though. Beside being the president to grow up the poorest Johnson was also the first president to be impeached. The radical Republicans in Congress were upset by Johnson's reconstruction efforts or lack thereof, so they tried to pass their own reconstructive measures. Congress relied on the army under control of Edward Stanton the Secretary of War at the time to help out. In order to stop Johnson from getting in the way Congress passed the Tenure of Office Act which prevented the president from firing a cabinet member already approved by congress. Johnson fired Stanton anyway. Congress wasn't too happy about this and swiftly impeached Johnson who barely missed conviction by one vote.
Johnson was defeated by Ulysses S. Grant in 1868 but his political career did not end there. In 1875 he was elected as a US Senator for Tennessee. Johnson died of a stroke later that year on July 31 in Elizabethton, Tennessee. He was 66 years old.