Who is Thomas Jonathan 'Stonewall' Jackson from Gods and Generals and what is their importance?

Thomas Jonathan 'Stonewall' Jackson had a poor upbringing in rural Virginia, but he graduated from West Point Military Academy before fighting in the Mexican war. After being promoted three times during the war, from lieutenant to major, he left the army to become an instructor at the Virginia Military Institute.

When the war begins, Jackson is convinced that the southern states are in the right. He views the federal government as an aggressor against his home that must be stopped. Lee assigns him to organize the defense of the arsenal at Harper's Ferry, after which, he is credited with turning the tide at the Battle of Bull Run. He is eventually given command of one half of the Army of Northern Virginia.

Over and over again Lee relies on Jackson in battle, as his troops consistently win against much greater numbers of enemy troops. His troops, in fact, are given the nick name of 'foot cavalry' because of how quickly they cover great distances. Jackson became a legend in his own time, and when he was shot at the Battle of Chancellorsville the entire army mourned his death.