What did I do?
First I roughly filled in the missing lower corners using the clone stamp and the healing brush. Then I removed specks and scratches from the background, smoothing it over to give it a softer feel. I then filled in the cracks and removed the scratches from her face and clothes, saving the gaping hole in the middle for last. Piecing together rest of the brooch, buttons and blouse required a high attention to detail and some creativity. Lastly, I heightened the contrast just a bit to make the textures in the clothes stronger.
*Original photo taken with gratitude from the US National Archives. Photographed by Mathew Brady, circa 1863.