Extra Credit Questions

[Gene C]

The center figure is very similar to the statue on top of the US Capitol, the letters in the center seem to be E PLURIBUS UNUM.

At the center of the base, it says Abraham Lincoln
The figure on the right seem to be of a woman.
(I enlarged the image on my computer to see it better)
The figure on the left looks like a soldier with a helmet.
The third clue about the transcontinental railroad has me stumped ???
It was completed in 1869

I'll guess the commemoration of the passing of the 13th amendment, which happened a few months after Lincoln died.