Ode to the Tube

I have yet to explain my love for the Tube.  I love the Tube.  Love love.  Even though most of the time it's really crowded and noisy and sweaty, it gets me everywhere.  With a swipe of my "Oyster" card, I am free to travel beneath the city of London.  Okay enough of that.  Really, I just think it's a cool system and I'd really like to know more of the history behind it.  And also, for some reason it's kind of empowering to me when I decide to go somewhere by myself and navigate just fine.