The Corps of Engineers' oldest and most time
honored insignia is the exclusive Essayons Button. It has not changed in
basic design since the war of 1812. It is still the required button for
the Army Engineers' uniform.
Evidence which could establish the actual facts concerning the designing and adoption of the Essayons Button probably burned at West Point in 1838, when the building containing the library and earliest official Corps of Military Academy records caught fire.
However, while early Army regulations mentioned the "Button of Engineers... with only the device and motto heretofore established", apparently no authoritative detailed description of the button appeared until 1840. The Army prescribed new uniforms on February 18, 1840, in General Orders 7, AGO, which officially described the button as follows:
An eagle holding in his beak a scroll with the word, 'Essayons,' a bastion with embrasures in the distance, surrounded by water, and rising sun; the figures to be of dead gold upon a bright field."
In 1902, when the Army adopted "regulation" buttons, it allowed only the Corps of Engineers to retain its own distinctive Essayons Button in recognition of the distinguished traditions that it symbolized.