What did the founders mean when they declared that all men are created equal? I ask because it is clearly evident that men are anything but equal. 

They differ immensely with regard to their physical features, intelligence and abilities.

They must certainly have meant that before the law, none of these differences should be taken into consideration. This is why 'Lady Liberty' is blindfolded.

Compare this view of equality to that which is referred to as equity.

In this view it is necessary to employ coercive means to ensure equal outcomes for unequal persons. 

This situation was foreseen by Kurt Vonnegut in his 1961 dystopian novelette entitled 'Harrison Bergeron'. in the world he portrays Vonnegut sees very coercive and personal measures being taken to ensure equal outcomes. A type of 'leveling the playing field' if you will.

The main character, Harrison Bergeron is very intelligent, and in order to prevent him from outperforming his less intelligent fellows, a device has been attached to him which emits a high pitched and disturbing sound every few minutes which prevents Bergeron from being able to gather his thoughts or think clearly, keeping him disoriented.

If you have not read it, I highly recommend it. It is an accurate depiction of the direction we are heading, and was penned nearly 65 years ago.