Check out this incredible photograph from the Civil War showing three men at the Washington Arsenal. Don't forget to read our guest post by GoDCer Andrew on the explosion that killed 21 at the Arsenal. Learn about the controversial figure Daniel E. Sickles, acquitted of murder in the first use of temporary insanity.

On June 17th, 1864, an explosion rocked the Washington Arsenal in the nation's capital. 19 women and girls were killed in the tragedy, and the victims were commemorated with a monument still standing today. Learn the story of the Washington Arsenal explosion.