For anyone, but mostly skyscraper neophytes and n00bs, looking for a brief primer on the history of skyscraper construction, the video below is very well made:
Race for the Skies: Chicago vs. New York
It frames today's skyscraper discipline as having stemmed largely from the upward competition by Chicago and New York that started in the late 19th century. It's 11 minutes long and a nice break from your workday.