The US Postal Service has created some 1862 sesquicentennial stamps.  They aren’t much more visually interesting than the aforementioned coins, though I admit, I haven’t seen the size of the stamps.  Super-huge stamps would give a bit more oomph than the watercolored drabness of the Antietam scene, and the New Orleans battle is a bit hard to make out on a small scale.

The Civil War: 1862 (Forever) – The Postal Store @ USPS.com.