Why were the two sides in the American Civil War known as the blues and grays?

The uniforms of the American Civil War (1861-1865), helped to distinguish between the Union soldiers of the North, and the Confederate soldiers from the south.

Early in the war the uniforms were provided by states, towns and even the local wealthy families and businessmen. It often created confusion due to the variety of styles and colours on both sides. Over time, blue became the official colour for the North and grey for the Confederate uniforms.

It became an acceptable slang to refer to each 'side' as either the blues or the greys.

Initially, the uniforms often created confusion as the officers of the Confederate South often wore double-breasted dark blue uniforms.