Well, I was able to answer the question, so I thought I would share with others:
"The 1911 is 'single action' only in that it requires the hammer to be cocked before the trigger is pulled for it to fire. Single action is as the name denotes - it does one thing...releases the hammer (or in some cases, the striker depending on the firearm). Double action, in the case of some semi autos and many revolvers, is that the trigger pull serves two functions - it both cocks the hammer and releases the hammer in one pull. 2 actions in one, basically.
The only 1911 I know of that offers a double action feature is made by Para Ordinance, and you can tell when you look at the unorthodox trigger as compared to regular 1911s. One nice thing about the 1911 is that its trigger system is one of the most customize-abe by a competent gunsmith for feel and weight. Actually, if you're entering the world of 1911s for the first time, you'll find that just about everything is customize-able, which is one of the reasons they are so fun."
Hope this is helpful to you.