History Of The Union Shield?

Does anyone know the history of the shield that's used on the obverse of the shield nickle, and on the reverse of IHC and how it originated?

I found some vague references to it at Wikipedia about how an artist during Lincoln's time designed the 13 stripes, or colonies, bound together by a ribbon, after the civil war ended.

It's also a symbol for the Union Pacific Railroad, and is again, somewhat modified, back on the reverse of the Lincoln Cent.

Thanks.