I believe you can get up to two weeks of "minute" or "tick" data from eSignal, and up to a year or so of daily data.
Beyond that, I haven't done it recently, but I used to get historical data by by going to "File" then "Download from HISTORYBANK.COM" in GlobalServer. The HISTORYBANK data is the Omega Research database, but I heard that at sometime in the near future they were going to cut that off.