Part Identification

I removed the lower section of the front fender between the wheel well and door on my 69 Barracuda. Underneath was a bracket that ran vertically with a flange on each side. Part of it is damaged. What is the term for this part and where could I purchase if I need to?

I believe you are seeing the inner fender splash shield. It is a metal panel with rubber side seals that prevented water from getting splashed into the door hinge area.
Here is an example of a complete kit (but you can buy the seals or shields separately from DMT, YO and other suppliers or if you need the metal, you can check used ones as they pop up for sale):
Mopar A Body 67-69 Barracuda Inner Fender Splash Shields WITH Seals AMD DMT